]> GREENSTONE DIGITAL LIBRARY Ian H. Witten, Stefan Boddie and John Thompson Department of Computer Science
University of Waikato, New Zealand Back to manual index Back to top index Greenstone is a suite of software for building and distributing digital library collections. It provides a new way of organizing information and publishing it on the Internet or on CD-ROM. Greenstone is produced by the New Zealand Digital Library Project at the University of Waikato, and developed and distributed in cooperation with UNESCO and the Human Info NGO. It is open-source software, available from http://greenstone.org under the terms of the Gnu General Public License. We want to ensure that this software works well for you. Please report any problems to greenstone@cs.waikato.ac.nz Greenstone gsdl-2.70 March 2006

This manual provides a comprehensive description of how to use the Greenstone software for accessing and building digital library collections. Section gives an overview of the capabilities of the software. Section explains how to use Greenstone collections. The interface is self-explanatory—the best way to learn is by doingand this section comprises the on-line help information for a typical collection. Section explains how to build your own library collections using the Greenstone Librarian Interface. Section introduces the administration facility that allows the system administrator to monitor what is going on and control who can build collections. Appendices list the features of the Greenstone software, and give a glossary of terms used throughout the Greenstone documentation.

The complete set of Greenstone documents includes four volumes: Greenstone Digital Library Installer's Guide Greenstone Digital Library User's Guide (this document) Greenstone Digital Library Developer's Guide Greenstone Digital Library: From Paper to Collection

Copyright © 2002 2003 2004 2005 2006 2007 by the New Zealand Digital Library Project at the University of Waikato, New Zealand. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled “GNU Free Documentation License.”

The Greenstone software is a collaborative effort between manypeople. Rodger McNab and Stefan Boddie are the principal architects andimplementors. Contributions have been made by David Bainbridge, GeorgeBuchanan, Hong Chen, Michael Dewsnip, Katherine Don, Elke Duncker, Carl Gutwin, Geoff Holmes, Dana McKay, JohnMcPherson, Craig Nevill-Manning, Dynal Patel, Gordon Paynter, Bernhard Pfahringer, ToddReed, Bill Rogers, John Thompson, and Stuart Yeates. Other members of the New ZealandDigital Library project provided advice and inspiration in the design ofthe system: Mark Apperley, Sally Jo Cunningham, Matt Jones, Steve Jones, Te TakaKeegan, Michel Loots, Malika Mahoui, Gary Marsden, Dave Nichols and Lloyd Smith. We would also like toacknowledge all those who have contributed to the GNU-licensed packagesincluded in this distribution: MG, GDBM, PDFTOHTML, PERL, WGET, WVWARE and XLHTML.

Greenstone is a comprehensive system for constructing and presenting collections of thousands or millions of documents, including text, images, audio and video.

A typical digital library built with Greenstone will contain many collections, individually organized—though they bear a strong family resemblance. Easily maintained, collections can be augmented and rebuilt automatically. There are several ways to find information in most Greenstone collections. For example, you can search for particular words that appear in the text, or within a section of a document. You can browse documents by title: just click on a book to read it. You can browse documents by subject. Subjects are represented by bookshelves: just click on a bookshelf to look at the books. Where appropriate, documents come complete with a table of contents: you can click on a chapter or subsection to open it, expand the full table of contents, or expand the full document into your browser window (useful for printing). The New Zealand Digital Library website (nzdl.org) provides numerous example collections. On the front page of each collection is a statement of its purpose and coverage, and an explanation of how the collection is organized. Most collections can be accessed by both searching and browsing. When searching, the Greenstone software looks through the entire text of all documents in the collection (this is called “full-text search”). In most collections the user can choose between indexes built from different parts of the documents. Some collections have an index of full documents, an index of paragraphs, and an index of titles, each of which can be searched for particular words or phrases. Using these you can find all documents that contain a particular set of words (the words may be scattered far and wide throughout the document), or all paragraphs that contain the set of words (which must all appear in the same paragraph), or all documents whose titles contain the words (the words must all appear in the document's title). There might be other indexes, perhaps an index of sections, and an index of section headings. Browsing involves lists that the user can examine: lists of authors, lists of titles, lists of dates, hierarchical classification structures, and so on. Different collections offer different browsing facilities.

Greenstone constructs full-text indexes from the document text—that is, indexes that enable searching on any words in the full text of the document. Indexes can be searched for particular words, combinations of words, or phrases, and results are ordered according to how relevant they are to the query. In most collections, descriptive data such as author, title, date, keywords, and so on, is associated with each document. This information is called metadata. Many document collections also contain full-text indexes of certain kinds of metadata. For example, many collections have a searchable index of document titles. Users can browse interactively around lists, and hierarchical structures, that are generated from the metadata that is associated with each document in the collection. Metadata forms the raw material for browsing. It must be provided explicitly or be derivable automatically from the documents themselves. Different collections offer different searching and browsing facilities. Indexes for both searching and browsing are constructed during a “building” process, according to information in a collection configuration file. Greenstone creates all index structures automatically from the documents and suppporting files: nothing is done manually. If new documents in the same format become available, they can be merged into the collection automatically. Indeed, for many collections this is done by processes that awake regularly, scout for new material, and rebuild the indexes—all without manual intervention.

Source documents come in a variety of formats, and are converted into a standard XML form for indexing by “plugins.” Plugins distributed with Greenstone process plain text, HTML, WORD and PDF documents, and Usenet and E-mail messages. New ones can be written for different document types (to do this you need to study the Greenstone Digital Library Developer's Guide). To build browsing structures from metadata, an analogous scheme of “classifiers” is used. These create browsing indexes of various kinds: scrollable lists, alphabetic selectors, dates, and arbitrary hierarchies. Again, Greenstone programmers can create new browsing structures.

Collections can contain text, pictures, audio and video. Non-textual material is either linked into the textual documents or accompanied by textual descriptions (such as figure captions) to allow full-text searching and browsing. Unicode, which is a standard scheme for representing the character sets used in the world's languages, is used throughout Greenstone. This allows any language to be processed and displayed in a consistent manner. Collections have been built containing Arabic, Chinese, English, French, M 0Å 1ori and Spanish. Multilingual collections embody automatic language recognition, and the interface is available in all the above languages (and more).

Collections are accessed over the Internet or published, in precisely the same form, on a self-installing Windows CD-ROM. Compression is used to compact the text and indexes. A Corba protocol supports distributed collections and graphical query interfaces. The New Zealand Digital Library (nzdl.org) provides many example collections, including historical documents, humanitarian and development information, technical reports and bibliographies, literary works, and magazines. Being open source, Greenstone is readily extensible, and benefits from the inclusion of Gnu-licensed modules for full-text retrieval, database management, and text extraction from proprietary document formats. Only through international cooperative efforts will digital library software become sufficiently comprehensive to meet the world's needs with the richness and flexibility that users deserve.

The Greenstone software is designed to be easy to use. Web-based and CD-ROM collections have interfaces that are identical. Installing the Greenstone software from CD-ROM on any Windows or Linux computer is very easy indeed; a standard installation setup program is used in conjunction with pre-compiled binaries. A collection can be used locally on the computer where it is installed; also, if this computer is connected to a network, the software automatically and transparently allows all other computers on the network to access the same collection. The next section describes how to install a Greenstone CD-ROM. Then we look at the searching and browsing facilities offered by a typical Greenstone collection, the “Demo” collection that is supplied with the Greenstone software. Other collections offer similar facilities; if you can use one, you can use them all. The following section explains how to customize the interface for your own requirements using the Preferences page.

The Greenstone digital library software itself comes on a CD-ROM, and you or your system manager have probably installed it on your system, following the instructions in the Greenstone Digital Library Installer's Guide. If so, Greenstone is already installed on your computer and you should skip the rest of this section. Some Greenstone collections come on a self-contained Greenstone CD-ROM that includes enough of the software to run just that collection. To use it, simply put it into the CD-ROM drive on any Windows PC. Most likely (if “autorun” is enabled on your PC), a window will appear inviting you to install the Greenstone software. If not, find the CD-ROM disk drive (on current Windows systems you can get this by clicking on the My Computer icon on the desktop) and double-click it, then the Setup.exe file inside it. The Greenstone Setup program will be entered, which guides you through the setup procedure. Most people respond yes to all the questions. When the installation procedure has finished, you'll find the library in the Programs submenu of the Windows Start menu, under the name of the collection (for example, “Development Library” or “United Nations University”). Once the software has been installed, the library will be entered automatically every time you re-insert the CD-ROM if autorun is enabled.

The easiest way to learn how to use a Greenstone collection is to try it out. Don't worry—you can't break anything. Click liberally: most images that appear on the screen are clickable. If you hold the mouse stationary over an image, most browsers will soon pop up a message that tells you what will happen if you click. Experiment! Choose common words like “the” and “and” to search for—that should evoke some responses, and nothing will break. Greenstone digital library systems usually comprise several separate collections—for example, computer science technical reports, literary works, internet FAQs, magazines. There will be a home page for the digital library system which allows you to access any publicly-accessible collection; in addition, each collection has its own “about” page that gives you information about how the collection is organized and the principles governing what is included in it. To get back to the “about” page at any time, just click on the “collection” icon that appears at the top left side of all searching and browsing pages. Figure shows a screenshot of the “Demo” collection supplied with the Greenstone software, which is a very small subset of the Development Library collection; we will use it as an example to describe the different ways of finding information. (If you can't find the Demo collection, use the Development Library instead; it looks just the same.) First, almost all icons are clickable. Several icons appear at the top of almost every page; Table shows you what they mean.

	This takes you to the “about” page
	This takes you to the Digital Library's home page, from which you can select another collection
	This provides help text similar to what you are reading now
	This allows you to set some user interface and searching options that will then be used henceforth

The “search … subjects … titles a-z … organization … how to” bar underneath gives access to the searching and browsing facilities. The leftmost button is for searching, and the ones to the right of it—four, in this collection—evoke different browsing facilities. These last four may differ from one collection to another. Table shows the five ways to find information in the Demo collection.

	Search for particular words
	Access publications by subject
	Access publications by title
	Access publications by organization
	Access publications by “how to” listing

You can search for particular words that appear in the text from the “search” page. (This is just like the “about” page shown in Figure , except that it doesn't contain the about this collection text.) The search page can be reached from other pages by pressing the search button. You can access publications by subject by pressing the subjects button. This brings up a list of subjects, represented by bookshelves that can be further expanded by clicking on them. You can access publications by title by pressing the titles a-z button. This brings up a list of books in alphabetic order. You can access publications by organization by pressing the organization button. This brings up a list of organizations. You can access publications by how to listing by pressing the how to button. This brings up a list of “how to” hints. All these buttons are visible in Figure . In the Demo collection, you can tell when you have arrived at an individual book because there is a photograph of its front cover (Figure ). Beside the photograph is a table of contents: the entry in bold face marks where you are, in this case Introduction and Summary —Section 1 of the chosen book. This table is expandable: click on the folders to open them or close them. Click on the open book at the top to close it. Underneath is the text of the current section (“The international demand for tropical butterflies …” in the example, beginning at the very bottom of the illustration). When you have read through it, there are arrows at the end to take you on to the next section or back to the previous one. Below the photograph are four buttons. Click on detach to make a new browser window for this book. (This is useful if you want to compare books, or read two at once.) If you have reached this book through a search, the search terms will be highlighted: the no highlighting button turns this off. Click on expand text to expand out the whole text of the current section, or book. Click on expand contents to expand out the whole table of contents so that you can see the titles of all chapters and subsections. In some collections, the documents do not have this kind of hierarchical structure. In this case, no table of contents is displayed when you get to an individual document—just the document text. In some cases, the document is split into pages, and you can read sequentially or jump about from one page to another.

When you are browsing around the collection, you will encounter the items shown in Table . From the search page, follow these simple steps to make a query: Specify what units you want to search: in the Demo collection you can search section titles or the full text of the books. Say whether you want to search for all or just some of the words Type in the words you want to search for into the query box Click the Begin Search button When you make a query, the titles of up to twenty matching documents will be shown. There is a button at the end to take you on to the next twenty. From there you will find buttons to take you on to the third twenty or back to the first twenty, and so on. However, for efficiency reasons a maximum of 100 is imposed on the number of documents returned. You can change these numbers by clicking the preferences button at the top of the page.

	Click on a book icon to read the corresponding book
	Click on a bookshelf icon to look at books on that subject
	View this document
	Open this folder and view contents
	Click on this icon to close the book
	Click on this icon to close the folder
	Click on the arrow to go on to the next section ...
	... or back to the previous section
	Open this page in a new window
	Expand table of contents
	Display all text
	Highlight search terms

Click the title of any document, or the little icon beside it, to open it. The icon may show a book, or a folder, or a page: it will be a book icon if you are searching books; otherwise if you are searching sections it will be a folder or page icon depending on whether or not the section found has subsections. Whatever you type into the query box is interpreted as a list of words called “search terms.” Each search term contains nothing but alphabetic characters and digits. Terms are separated by white space. If any other characters such as punctuation appear, they serve to separate terms just as though they were spaces. And then they are ignored. You can't search for words that include punctuation. For example, the query Agro-forestry in the Pacific Islands: Systems for Sustainability (1993) will be treated the same as Agro forestry in the Pacific Islands Systems for Sustainability 1993 There are two different kinds of query. Queries for all the words. These look for documents (or chapters, or titles) that contain all the words you have specified. Documents that satisfy the query are displayed. Queries for some of the words. Just list some terms that are likely to appear in the documents you are looking for. Documents are displayed in order of how closely they match the query. When determining the degree of match, the more search terms a document contains, the closer it matches; rare terms are more important than common ones; short documents match better than long ones. Use as many search terms as you like—a whole sentence, or even a whole paragraph. If you specify only one term, it doesn't much matter whether you use an all or a some query, except that in the second case the results will be sorted by the search term's frequency of occurrence. In most collections you can choose different indexes to search. For example, there might be author or title indexes. Or there might be chapter or paragraph indexes. Generally, the full matching document is returned regardless of which index you search. If documents are books, they will be opened at the appropriate place. While the above is enough to meet most searching needs, some more advanced search features are provided. These are activated from the Preferences page, which is reached by clicking the preferences button at the top of the page—see Section below. After changing your preferences, do not click your browser's Back button—that would undo the changes. Instead, click any of the buttons on the search/browse bar. When you specify search terms, you can choose whether upper and lower case must match between the query and the document: this is called “case sensitivity.” You can also choose whether to ignore word endings or not: this is called “stemming.” Under Search options on the Preferences page you will see a pair of buttons labeled ignore case differences and upper/lower case must match; these control the case sensitivity of your queries. Below is a pair of buttons labeled ignore word endings and whole word must match: these control stemming. For example, if the buttons ignore case differences and ignore word endings are selected, the query African building will be treated the same as africa builds because the uppercase letter in “African” will be transformed to lowercase, and the suffixes “n” and “ing” will be removed from “African” and “building” respectively (also, “s” would be removed from “builds”). Generally case differences and word endings should be ignored unless you are querying for particular names or acronyms. If your query includes a phrase in quotation marks, only documents containing that phrase, exactly as typed, will be returned. If you want to use phrase searching, you need to learn a little about how it works. Phrases are processed by a post-retrieval scan. First the query is issued in the normal way—all the words in the phrase are included as search terms—and then the documents returned are scanned to eliminate those in which that phrase does not appear. During the post-retrieval scan, phrases are checked just as they are, including any punctuation. For example, the query what's a “post-retrieval scan?” will first retrieve all documents that match all of the words what s a post retrieval scan and then the documents returned will be checked for the phrase post-retrieval scan? Phrase matches are case-insensitive if ignore case differences is set on the Preferences page. In advanced query mode, which can be selected on the Preferences page, the queries for all of the words, described above, are actually Boolean queries. They consist of a list of terms joined by logical operators & (and), | (or), and ! (not). Absent operatorsbetween search terms are interpreted as & (and): thus a query without any operators returns documents that match all the terms. If the words AND, OR, and NOT appear in your query they are treated as ordinary search terms, not operators. For operators you must use &, |, and !. In addition, parentheses can be used for grouping. When you switch on the “search history” feature on the Preferences page you will be shown your last few searches, along with a summary of how many results they generated. Click the button beside one of the previous searches to copy the text into the search box. This makes it easy to repeat slightly modified versions of previous queries.

When you click the preferences button at the top of the page you will be able to change some features of the interface to suit your own requirements. The preferences depend on the collection; an example is shown in Figure . When you adjust your search preferences, you should press the set preferences button shown in Figure . After setting preferences, do not use your browser's “back” button—that would unset them! Instead, click one of the buttons on the access bar near the top of the page. Some collections comprise several subcollections, which can be searched independently or together, as one unit. If so, you can select which subcollections to include in your searches on the Preferences page. Each collection has a default presentation language, but you can switch to a different language if you like. You can also alter the encoding scheme used by Greenstone for output to the browser—the software chooses sensible defaults, but with some browsers better visual results can be used by switching to a different encoding scheme. All collections allow you to switch from the standard graphical interface format to a textual one. This is particularly useful for visually impaired users who use large screen fonts or speech synthesizers for output. Depending on the collection, there may be other options you can set that control the presentation. Collections of web pages allow you to suppress the Greenstone navigation bar at the top of each document page, so that once you have done a search you land at the exact web page that matches without any Greenstone header. To do another search you will have to use your browser's “back” button. These collections also allow you to suppress Greenstone's warning message when you click a link that takes you out of the digital library collection and on to the web itself. And in some web collections you can control whether the links on the “Search Results” page take you straight to the actual URL in question, rather than to the digital library's copy of the page. Under Search preferences in Figure , the first pair of buttons allows you to get a large query box, so that you can easily do paragraph-sized searching. In Greenstone, it is surprisingly quick to search for large amounts of text. The next two pairs of buttons control the kind of text matching in the searches that you make. The first set (labeled “case differences”) controls whether upper and lower case must match. The second (“word endings”) controls whether to ignore word endings or not. Using the next button pair you can switch to the “advanced” query mode described above, which allows you to specify more precise queries by combining terms using AND (&), OR (|), and NOT (!). You can turn the search history feature, described above, on and off. Finally, you can control the number of hits returned, and the number presented on each screenful, through the last entry in Figure .

The simplest way to build new collections is to use Greenstone's “librarian” interface (GLI). This allows you to collect sets of documents, import or assign metadata, and build them into a Greenstone collection. It supports five basic activities, which can be interleaved but are nominally undertaken in this order: Copy documents from the computer's file space, including existing collections, into the new collection. Any existing metadata remains “attached” to these documents. Documents may also be gathered from the web through a built-in mirroring facility. Enrich the documents by adding further metadata to individual documents or groups of documents. Design the collection by determining its appearance and the access facilities that it will support. Build the collection using Greenstone. Preview the newly created collection, which will have been installed on your Greenstone home page as one of the regular collections. The librarian interface allows you to add what people call “external” metadata to documents, metadata that pertains to the document as a whole. But documents often need to be structured into sections and subsections, and “internal” metadata might be associated with each part. In Greenstone, source documents can be tagged with this information, and we explain this in Section . Finally, an alternative way of building collections is provided by the Collector, which helps you create new collections, modify or add to existing ones, or delete collections. It predates the librarian interface, and for most practical purposes the librarian interface should be used instead of the Collector. It is described in Section . To harness the full power of Greenstone to build advanced collections, you will also need to read Chapter of the Developer's Guide.

To convey the operation of Greenstone's librarian interface, we work through a simple example. Figures to are screen snapshots at various points during the interaction. This example uses documents in the Development Library Subset (DLS) collection, which is distributed with Greenstone. For expository purposes, the walkthrough takes the form of a single pass through the steps listed above. A more realistic pattern of use, however, is for users to switch back and forth through the various stages as the task proceeds. The librarian interface can be run in one of four modes: Librarian Assistant, Librarian, Library Systems Specialist, and Expert. Modes control the level of detail within the interface, and can be changed through 'Preferences' in the 'File' menu. The walkthrough in this section assumes that the librarian interface is operating in the default mode, Librarian. Launch the librarian interface under Windows by selecting Greenstone Digital Library from the Programs section of the Start menu and choosing Librarian Interface. If you are using Unix, instead type cd ~/gsdl cd gli ./gli.sh where ~/gsdl is the directory containing your Greenstone system. To begin, you must either open an existing collection or start a new one. Figure shows the user in the process of starting a new collection. She has selected New from the file menu and begun to fill out general information about the collection—its title, the E-mail address of the person responsible for it, and a brief description of the content—in the popup window. The collection title is a short phrase used throughout the digital library to identify the collection's content: existing collections have names like Food and Nutrition Library, World Environmental Library, and so on. When you type the title, the system assigns a unique mnemonic identifier, the collection “name”, for internal use (you can change it if you like). The E-mail address specifies the first point of contact for any problems encountered with the collection. The brief description is a statement describing the principles that govern what is included in the collection. It appears under the heading About this collection on the collection's initial page.

At this point, the user decides whether to base the new collection on the same structure as an existing collection, or to build an entirely new kind of collection. In Figure she has chosen to base it on the Development Library Subset collection. This implies that the “DLS” metadata set which is used in this collection will be used for the new collection. (In fact, this metadata set has been used to build several Greenstone collections that share a common structure and organization but with different content, including the Development Library Subset and Demo collections delivered as samples with Greenstone.) The DLS metadata set contains these items: Title Subject Language Organization Keyword (i.e.”Howto”). (There is, in addition, a metadata item called AZList which is used to determine which bucket of the alphabetic list contains the document's title, with values like “A-B” or “C-D-E”. This is used to give precise control over thedivisions in the list. For most other collections it is absent, and Greenstone assigns the buckets itself.) If, instead, the user had chosen “New Collection” at this point, she would have been asked to select what metadata sets should be used in the new collection. Three standard sets are pre-supplied: Dublin Core, the DLS metadata set mentioned above, and a set that comprises metadata elements extracted automatically by Greenstone from the documents in the collection. The user can also create new metadata sets using a popup panel activated through the “metadata” menu. Several different metadata sets can be associated with the same collection; the system keeps them distinct (so that, for example, documents can have both a Dublin Core Title and a DLS Title). The different sets are clearly distinguished in the interface. Behind the scenes, metadata sets are represented in XML. After clicking the OK button on the “new collection” popup, the remaining parts of the interface, which were grayed out before, become active. The Gather panel, selected by the eponymous tab near the top of Figure , is displayed initially. This allows the user to explore the local file space and existing collections, gathering up selected documents for the new collection. The panel is divided into two sections, the left for browsing existing structures and the right for the documents in the collection. Operations available at this stage include: Navigating the existing file structure hierarchy, and the one being created, in the usual way. Dragging and dropping files into the new collection. Multiple selection of files. Dragging and dropping entire sub-hierarchies. Deleting documents from the nascent collection. Creating new sub-hierarchies within the collection. Filtering the files that are visible, in both the local file system and the collection, based on predetermined groups or on standard file matching terms. Invoking the appropriate program to display the contents of a selected file, by double-clicking it. Care is taken to deal appropriately with name clashes when files of the same name in different parts of the computer's directory structure are copied into the same folder of the collection. In Figure the user is using the interactive file tree display to explore the local file system. At this stage, the collection on the right is empty; the user populates it by dragging and dropping files of interest from the left to the right panel. Such files are “copied” rather than “moved”: so as not to disturb the original file system. The usual techniques for multiple selection, dragging and dropping, structuring the new collection by creating subdirectories (“folders”), and deleting files from it by moving them to a trashcan, are all available. Existing collections are represented by a subdirectory on the left called “Greenstone Collections,” which can be opened and explored like any other directory. However, the documents therein differ from ordinary files because they already have metadata attached, and this is preserved when they are moved into the new collection. Conflicts may arise because their metadata may have been assigned using a different metadata set from the one in use for the new collection, and the user must resolve these. In Figure the user has selected some documents from an existing collection and dragged them into the new one. The popup window explains that the metadata element Organization cannot be automatically imported, and asks the user to either select a metadata set and press Add to add the metadata element to that set, or choose a metadata set, then an element, and press Merge to effectively rename the old metadata element to the new one by merging the two. Metadata in subsequent documents from the same collection will automatically be handled in the same way. When large file sets are selected, dragged, and dropped into the new collection, the copying operation may take some time—particularly if metadata conversion is involved. To indicate progress, the interface shows which file is being copied and what percentage of files has been processed. Special facilities are provided for dealing with large file sets. For example, the user can choose to filter the file tree to show only certain files, using a dropdown menu of file types displayed underneath the trees. In Figure , only the HTM and HTML files are being shown (and only these files will be copied by drag and drop). The next phase in collection building is to enrich the documents by adding metadata. The Enrich tab brings up a new panel of information (Figure ), which shows the document tree representing the collection on the left and on the right allows metadata to be added to individual documents, or groups of documents. Documents that are copied during the first step come with any applicable metadata attached. If a document is part of a Greenstone collection, previously defined metadata is carried over to the new collection. Of course, this new collection may have a different metadata set, or perhaps just a subset of the defined metadata, and only metadata that pertains to the new collection's set is carried over. Resolution of such conflicts may require user intervention via a supplementary dialog (Figure ). Any choices made are remembered for subsequent file copies. The Enrich panel allows metadata values to be assigned to documents in the collection. For example, new values can be added to the set of existing values for an element. If the element's values have a hierarchical structure, the hierarchy can be extended in the same way.

Metadata values can also be assigned to folders, in just the same way. Documents in these folders for which this metadata is unspecified inherit the metadata values. However, they can subsequently be overridden by supplying different ones for the document itself. Operations at this stage include: Assigning new and existing metadata values to documents. Assigning metadata to an individual document. Assigning metadata to a folder (this is inherited by all documentsin the folder, including those in nested folders). Assigning hierarchical metadata, whose structure can be dynamically updated if required. Editing or updating assigned metadata. Reviewing the metadata assigned to a selection of files and directories. For our walkthrough example, in Figure the user has selected the folder ec121e and assigned “EC Courier” as its Organization metadata. The buttons for updating and removing metadata become active depending on what selections have been made. During the enrichment phase, or indeed at any other time, the user can choose to view all the metadata that has been assigned to documents in the collection. This is done by selecting a set of documents and choosing Assigned Metadata from the metadata sets menu, which brings up a popup window like that in Figure that shows the metadata in spreadsheet form. For large collections it is useful to be able to view the metadata associated with certain document types only, and if the user has specified a file filter as mentioned above, only the selected documents are shown in the metadata display. The panel in Figure allows the user to edit metadata sets. Here, the user is looking at the Subject element of the DLS set. The values of this element form a hierarchy, and the user is examining, and perhaps changing, the list of values assigned to it. The same panel also allows you to change the “profile” for mapping elements of one metadata set to another. This profile is created when importing documents from collections that have pre-assigned metadata.

The Design panel (Figures —) allows one to specify the structure, organization, and presentation of the collection being created. As noted earlier, the result of this process is recorded in a “collection configuration file,” which is Greenstone's way of expressing the facilities that a collection requires. This step involves a series of separate interaction screens, each dealing with one aspect of the collection design. In effect, it serves as a graphical equivalent to the usual process of editing the configuration file manually. Operations include: Reviewing and editing collection-level metadata such as title, author and public availability of the collection. Defining what full-text indexes are to be built. Creating sub-collections and having indexes built for them. Adding or removing support for predefined interface languages. Constructing a list of plug-ins to be used, and their arguments. Presenting the list to the user for review and modification. Configuring individual plug-ins. Constructing a list of “classifiers,” their arguments, assignment and configuration. Assigning formatting strings to various controls within the collection, thus altering its appearance. Reviewing the metadata sets, and their elements, used in the collection. In Figure the user has clicked the Design tab and is reviewing the general information about the collection, entered when the new collection was created. On the left are listed the various facets that the user can configure: General, Document Plug-ins, Search Types, Search Indexes, Partition Indexes, Cross-Collection Search, Browsing Classifiers, Format Features, Translate Text, Metadata Sets. Appearance and functionality varies between these. For example, clicking the Plug-in button brings up the screen shown in Figure , which allows you to add, remove or configure plug-ins, and change the order in which the plug-ins are applied to documents. Plug-ins and classifiers have many different arguments or “options” that the user can supply. The dialog box in Figure shows the user specifying arguments to some of the plug-ins. The grayed-out fields become active when the user adds the option by clicking the tick-box beside it. Because Greenstone is a continually growing open-source system, the number of options tends to increase as developers add new facilities. To help cope with this, Greenstone has a “plug-in information” utility program that lists the options available for each plug-in, and the librarian interface automatically invokes this to determine what options to show. This allows the interactive user interface to automatically keep pace with developments in the software.

The Create panel (Figure ) is used to construct a collection based on the documents and assigned metadata. The brunt of this work is borne by the Greenstone code itself. The user controls this external process through a series of separate interaction screens, each dealing with the arguments provided to a certain stage of the creation process. The user observes the building process though a window that shows not only the text output generated by Greenstone's importing and index-building scripts, but also progress bars that indicate the overall degree of completion of each script. Figure shows the Create view. At the top are shown some options that can be applied during the creation process. The user selects appropriate values for the options. This figure illustrates a popup “tool tip” that is available throughout the interface to explain the function of each argument. When satisfied with the arguments, the user clicks Build Collection. Greenstone continually prints text that indicates progress, and this is shown along with a more informative progress bar. The Preview Collection button (Figure ) is used to view the collection that has been built. Clicking this button launches a web browser showing the home page of the collection (Figure ). In practice, previewing often shows up deficiencies in the collection design, or in the individual metadata values, and the user frequently returns to earlier stages to correct these. This button becomes active once the collection has been created. The newly created collection will also have been installed on your Greenstone home page as one of the regular collections. On-line help is always available, and is invoked using the Help item at the right of the main menu bar at the top of each of the Figures. This opens up a hierarchically structured file of help text, and account is taken of the user's current context to highlight the section that is appropriate to the present stage of the interaction. Furthermore, as noted above, whenever the mouse is held still over any interactive object a small window pops up to give a textual “tool tip,” as illustrated near the bottom of Figure .

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Source documents often need to be structured into sections and subsections, and this information needs to be communicated to Greenstone so that it can preserve the hierarchical structure. Also, metadata - typically the title - might be associated with each section and subsection. The source documents from an OCR process are typically a set of word processor files, including images. If these are represented as MicrosoftWord files, they can be input into Greenstone using the Word plugin. Alternatively, they can be converted to HTML and input using the HTML plugin. In either case, the hierarchical structure of a document may be indicated by inserting tags in the text as follows: <!-- <Section> <Description> <Metadata name="Title">Realizing human rights for poor people: Strategies for achieving the international development targets</Metadata> </Description> --> (text of section goes here) <!-- </Section> --> The <!-- ... --> markers are used because they indicate comments in HTML; thus these section tags will not affect document formatting. You must include these markers around your section tags, even if the document you are working with is not HTML (e.g. if it's a Microsoft Word file). In the Description part (between the <Description> and </Description> tags) other kinds of metadata can be specified, but this is not done for the style of collections we are describing here. It is important to remember that you are creating a hierarchical table of contents when you insert section tags into your document. This means that sections can be nested within other sections. In fact, all sections must be nested within a single enclosing section that encompasses the entire document. The following example demonstrates a document with two chapters, the second of which contains two subsections. For real examples of sourcedocuments tagged in this way, look at the source documents for the Demo or DLS collections. <!-- <Section> <Description> <Metadata name="Title">My Document</Metadata> </Description> <Section> <Description> <Metadata name="Title">Chapter 1</Metadata> </Description> --> (text of chapter 1 goes here) <!-- </Section> <Section> <Description> <Metadata name="Title">Chapter 2</Metadata> </Description> <Section> <Description> <Metadata name="Title">Subsection 1</Metadata> </Description> --> (text of sub-section 1 goes here) <!-- </Section> <Section> <Description> <Metadata name="Title">Subsection 2</Metadata> </Description> --> (text of sub-section 2 goes here) <!-- </Section> </Section> </Section> --> Note that metadata assigned from within a section tag in a source document takes precedence over that assigned to the document as a whole. This means that you should not explicitly specify Title metadata for the top-level section within a source document unless you want it to override the title you gave it when specifying metadata. In the above example, unless you want to override the document's existing title you should omit the line that reads: <Metadata name="Title">My Document</Metadata>

The Collector is a facility that helps you create new collections, modify or add to existing ones, or delete collections. To do this you will be guided through a sequence of web pages which request the information that is needed. The sequence is self-explanatory: this section takes you through it. As an alternative to using the Collector, you can also build collections from the command line—the first few pages of the Developer's Guide give a detailed walk-through of how to do this. The Collector predates the librarian interface described in Section , and for most practical purposes the librarian interface should be used instead of the Collector. Building and distributing information collections carries responsibilities that you should reflect on before you begin. There are legal issues of copyright: being able to access documents doesn't mean you can necessarily give them to others. There are social issues: collections should respect the customs of the community out of which the documents arise. And there are ethical issues: some things simply should not be made available to others. The pen is mightier than the sword!—be sensitive to the power of information and use it wisely. To access the Collector, click the appropriate link on the digital library home page. In Greenstone, the structure of a particular collection is determined when the collection is set up. This includes such things as the format of the source documents, how they should be displayed on the screen, the source of metadata, what browsing facilities should be provided, what full-text search indexes should be provided, and how the search results should be displayed. Once the collection is in place, it is easy to add new documents to it—so long as they have the same format as the existing documents, and the same type of metadata is provided, in exactly the same way. The Collector has the following basic functions: create a new collection with the same structure as an existing one; create a new collection with a different structure from existing ones; add new material to an existing collection; modify the structure of an existing collection; delete a collection; and write an existing collection to a self-contained, self-installing cd-rom. Figure shows the Collector being used to create a new collection, in this case from a set of html files stored locally. You must first decide whether to work with an existing collection or build a new one. The former case covers options 1 and 2 above; the latter covers options 3—6. In Figure , the user opts to create a new collection.

Either way it is necessary to log in before proceeding. Note that in general, people use their web browser to access the collection-building facility on a remote computer, and build the collection on that server. Of course, we cannot allow arbitrary people to build collections (for reasons of propriety if nothing else), so Greenstone contains a security system which forces people who want to build collections to log in first. This allows a central system to offer a service to those wishing to build information collections and use that server to make them available to others. Alternatively, if you are running Greenstone on your own computer you can build collections locally, but it is still necessary to log in because other people who use the Greenstone system on your computer should not be allowed to build collections without prior permission.

Upon completion of login, the page in Figure appears. This shows the sequence of steps that are involved in collection building. They are: Collection information Source data Configuring the collection Building the collection Viewing the collection. The first step is to specify the collection's name and associated information. The second is to say where the source data is to come from. The third is to adjust the configuration options, a step that becomes more useful as you gain experience with Greenstone. The fourth step is where all the (computer's) work is done. During the “building” process the system makes all the indexes and gathers together any other information that is required to make the collection operate. The fifth step is to view the collection that has been created. These five steps are displayed as a linear sequence of gray buttons at the bottom of the screen in Figure , and at the bottom of all other pages generated by the Collector. This display helps users keep track of where they are in the process. The button that should be clicked to continue the sequence is shown in green (collection information in Figure ). The gray buttons (all the others, in Figure ) are inactive. The buttons change to yellow as you proceed through the sequence, and the user can return to an earlier step by clicking the corresponding yellow button in the diagram. This display is modeled after the “wizards” that are widely used in commercial software to guide users through the steps involved in installing new software.

The next step in the sequence, collection information, is shown in Figure . When creating a new collection, it is necessary to enter some information about it: title, contact E-mail address, and brief description. The collection title is a short phrase used through the digital library to identify the content of the collection. Example titles include Food and Nutrition Library, World Environmental Library, Development Library, and so on. The E-mail address specifies the first point of contact for any problems encountered with the collection. If the Greenstone software detects a problem, a diagnostic report may be sent to this address. Finally, the brief description is a statement describing the principles that govern what is included in the collection. It appears under the heading About this collection on the first page when the collection is presented. The user's current position in the collection-building sequence is indicated by an arrow that appears in the display at the bottom of each screen—in this case, as Figure shows, the collection information stage. The user proceeds to Figure by clicking the green source data button.

Figure is the point where the user specifies the source text that comprises the collection. You may either base your collection on a default structure that is provided, or on the structure of an existing collection. If you opt for the default structure, the new collection may contain html documents (files ending in .htm, .html), or plain text documents (files ending in .txt, .text), Microsoft Word documents (files ending in .doc), PDF documents (files ending in .pdf) or E-mail documents (files ending in .email). More information about the different document formats that can be accommodated is given in the section on “Document formats” below. If you base your new collection on an existing one, the files in the new collection must be exactly the same type as those used to build the existing one. Note that some collections use non-standard input file formats, while others use metadata specified in auxiliary files. If your new input lacks this information, some browsing facilities may not work properly. For example, if you clone the Demo collection you may find that the subjects, organization, and how to buttons don't work. Boxes are provided to indicate where the source documents are located: up to three separate input sources can be specified in Figure . If you need more, just click the button marked “more sources.” There are three kinds of specification: a directory name on the Greenstone server system (beginning with “file://”) an address beginning with “http://” for files to be downloaded from the web an address beginning with “ftp://” for files to be downloaded using anonymous FTP. If you use file:// or ftp:// to specify a file, that file will be downloaded. If you use http:// it depends on whether the URL gives you a normal web page in your browser, or a list of files. If a page, that page will be downloaded—and so will all pages it links to, and all pages they link to, etc.—provided they reside on the same site, below the URL. If you use file:// or ftp:// to specify a folder or directory, or give a http:// URL that leads to a list of files, everything in the folder and all its subfolders will be included in the collection. You can specify sources of more than one type. In this case (Figure ) the new collection will contain documents taken from a local file system as well as a remote web site, which will be mirrored during the building process. When you click the configure collection button to proceed to the next stage of building, the Collector checks that all the sources of input you specified can be reached. This might take a few seconds, or even a few minutes if you have specified several sources. If one or more of the input sources you specified is unavailable, you will be presented with a page like that in Figure , where the unavailable sources are marked (both of them in this case).

Sources might be unavailable because the file, FTP site or URL does not exist; you need to dial up your ISP first; you are trying to access a URL from behind a firewall. The last case is potentially the most mysterious. It occurs if you normally have to present a username and password to access the Internet Sometimes it happens that you can see the page from your Web browser if you enter the URL, but the Collector claims that it is unavailable. The explanation is that the page in your browser may be coming from a locally cached copy. Unfortunately, locally cached copies are invisible to the Collector. In this case we recommend that you download the pages using your browser first.

Figure shows the next stage. The construction and presentation of all collections is controlled by specifications in a special collection configuration file (see below). Advanced users may use this page to alter the configuration settings. Most, however, will proceed directly to the final stage. Indeed, in Figure both the configure collection and the build collection buttons are displayed in green, signifying that step 3 can be bypassed completely. In our example the user has made a small modification to the default configuration file by including the file_is_url flag with the html plugin. This flag causes URL metadata to be inserted in each document, based on the filename convention that is adopted by the mirroring package. This metadata is used in the collection to allow readers to refer to the original source material, rather than to a local copy.

Figure shows the “building” stage. Up until now, the responses to the dialog have merely been recorded in a temporary file. The building stage is where the action takes place. During building, indexes for both browsing and searching are constructed according to instructions in the collection configuration file. The building process takes some time: minutes to hours, depending on the size of the collection and the speed of your computer. Some very large collections take a day or more to build. When you reach this stage in the interaction, a status line at the bottom of the web page gives feedback on how the operation is progressing, updated every five seconds. The message visible in Figure indicates that when the snapshot was taken, Title metadata was being extracted from an input file. Warnings are written if input files or URLs are requested that do not exist, or exist but there is no plugin that can process them, or the plugin cannot find an associated file, such as an image file embedded in a html document. The intention is that you will monitor progress by keeping this window open in your browser. If any errors cause the process to terminate, they are recorded in this status area. You can stop the building process at any time by clicking on the stop building button in Figure . If you leave the web page (and have not cancelled the building process with the stop building button), the building operation will continue, and the new collection will be installed when the operation completes. When the collection is built and installed, the sequence of buttons visible at the bottom of Figures — appears at the bottom of Figure , with the View collection button active. This takes the user directly to the newly built collection. Finally, there is a facility for E-mail to be sent to the collection's contact E-mail address, and to the system's administrator, whenever a collection is created (or modified.) This allows those responsible to check when changes occur, and monitor what is happening on the system. The facility is disabled by default but can be enabled by editing the main.cfg configuration file (see the Greenstone Digital Library Developer's Guide, Section ). When you enter the Collector you have to specify whether you want to create an entirely new collection or work with an existing one, adding data to it or deleting it. By creating all searching and browsing structures automatically from the documents themselves Greenstone makes it easy to add new information to existing collections. Because no links are inserted by hand, when new documents in the same format become available they can be merged into the collection automatically. To work with an existing collection, you first select the collection from a list that is provided. Some collections are “write protected” and cannot be altered: these ones don't appear in the selection list. With the collection, you can Add more data and rebuild the collection Edit the collection configuration file Delete the collection entirely Export the collection to CD-ROM. The files that you specify will be added to the collection. Make sure that you do not re-specify files that are already in the collection—otherwise two copies will be included. Files are identified by their full pathname, web pages by their absolute web address. You specify directories and files just as you do when building a new collection. If you add data to a collection and for some reason the building process fails, the old version of the collection remains unchanged. Advanced users can edit the collection configuration file, just as they can when a new collection is built. You will be asked to confirm whether you really want to delete the collection. Once deleted, Greenstone can not bring the collection back! You can export the collection in a form that allows it to be written to a self-contained, self-installing Greenstone CD-ROM for Windows. Because commercial software that creates self-installing CD-ROMs is expensive, this facility includes a homegrown installer module. When you export the collection, the dialogue informs you of the directory name in which the result has been placed. The entire contents of the directory should be written on to CD-ROM using a standard CD-writing utility. The immense variety of different possible Windows configurations has made it difficult for us to test and debug the Greenstone installer under all possible conditions. Although the installer produces CD-ROMs that operate on most Windows systems, it is still under development. If you experience problems and you possess a commercial installation package (e.g. InstallShield), you can use it to create CD-ROMs from the information that Greenstone provides. The above-mentioned export directory contains four files that relate to the installation process, and three subdirectories that contain the complete collection and software. Remove the four files and use InstallShield to make a CD-ROM image that installs these directories and creates a shortcut to the program gsdl\server.exe. When building collections, Greenstone processes each different format of source document by seeking a “plugin” that can deal with that particular format. Plugins are specified in the collection configuration file. Greenstone generally uses the filename to determine document formats—for example, foo.txt is processed as a text file, foo.html as html, and foo.doc as a Word file. Here is a summary of the plugins that are available for widely-used document formats. More detail about these plugins, and additional plugins for less commonly-used formats, can be found in the Greenstone Digital Library Developer's Guide. TEXTPlug interprets a plain text file as a simple document. It adds title metadata based on the first line of the file. HTMLPlug processes html files. It extracts title metadata based on the <title> tag; other metadata expressed using html's metatag syntax can be extracted too. There are many options available with this plugin, documented in the Greenstone Digital Library Developer's Guide. WORDPlug imports Microsoft Word documents. There are many different variants on the Word format—and even Microsoft programs frequently make conversion errors. Greenstone uses independent programs to convert Word files to html. For some older Word formats the system resorts to a simple extraction algorithm that finds all text strings in the input file. PDFPlug imports documents in PDF Adobe's Portable Document Format. Like WORDPlug, it uses an independent program, in this case pdftohtml, to convert PDF files to html. As with WORDPlug, by default collections will display the html equivalent of the file when the user clicks the document icon; however, the format strings in the collection configuration file can be adjusted to give the user access to the original PDF file instead, and we recommend that you do this. Again, just replace the <link> … </link> tags by <srclink> … </srclink> ones. The pdftohtml program fails on some PDF files. What happens is that the conversion process takes an exceptionally long time, and often an error message relating to the conversion process appears on the screen. If this occurs, the only solution that we can offer is to remove the offending document from the collection. Also, PDFPlug cannot handle encrypted PDF files. PSPlug imports documents in PostScript. It works best if a standard Linux program, called ps2ascii, is already installed on your computer. This is available on most Linux installations, but not on Windows. If this program is not available, PSPlug resorts to a simple text extraction algorithm. EMAILPlug imports files containing E-mail, and deals with common E-mail formats such as are used by the Netscape, Eudora, and Unix mail readers. Each source document is examined to see if it contains an E-mail, or several E-mails joined together in one file, and if so its contents are processed. The plugin extracts Subject, To, From, and Date metadata. However, this plugin does not yet handle MIME-encoded E-mails properly—although legible, they often look rather strange. ZIPPlug plugin handles the following compressed and/or archived input formats : gzip (.gz, .z, .tgz, .taz) , bzip (.bz) , zip (.zip, .jar) , and tar (.tar). It relies on the programs gunzip, bunzip, unzip, and tar, which are standard Linux utilities. ZIPPlug is disabled on Windows computers.

An “administrative” facility is included with every Greenstone installation.To access this facility, click the appropriate link on the front page. The entry page, shown in Figure , gives information about each of the collections offered by the system. Note that all collections are included—for there may be “private” ones that do not appear on the Greenstone home page. With each is given its short name, full name, whether it is publicly displayed, and whether or not it is running. Clicking a particular collection's abbreviation (the first column of links in Figure ) brings up information about that collection, gathered from its collection configuration file and from other internal structures created for that collection. If the collection is both public and running, clicking the collection's full name (the second link) takes you to the collection itself. A collection named wohiex, for Women's History Excerpt, is visible near the bottom of Figure . Figure shows the information that is displayed when this link is clicked. The first section gives some information from the configuration file, and the size of the collection (about 1000 documents, about a million words, over 6 Mb). The next sections contain internal information related to the communication protocol through which collections are accessed. For example, the filter options for “QueryFilter” show the options and possible values that can be used when querying the collection. The administrative facility also presents configuration information about the installation and allows it to be modified. It facilitates examination of the error logs that record internal errors, and the user logs that record usage. It enables a specified user (or users) to authorize others to build collections and add new material to existing ones. All these facilities are accessed interactively from the menu items at the left-hand side of Figure .

There are two configuration files that control Greenstone's operation, the site configuration file gsdlsite.cfg and the main configuration file main.cfg. The gsdlsite.cfg file is used to configure the Greenstone software for the site where it is installed. It is designed for keeping configuration options that are particular to a given site. Examples include the name of the directory where the Greenstone software is kept, the http address of the Greenstone system, and whether the fastcgi facility is being used.The entries in this file are described in the Greenstone Digital Library Installation Guide. The main.cfg file contains information that is common to the interface of all collections served by a Greenstone site. It includes the E-mail address of the system maintainer, whether the status and collector pages are enabled, whether logs of user activity are kept, and whether Internet “cookies” are used to identify users.

Three kinds of logs can be examined: usage logs, error logs and initialization logs. The last two are only really of interest to people maintaining the software. All user activity—every page that each user visits—can be recorded by the Greenstone software, though no personal names are included in the logs. Logging, disabled by default, is enabled by including the lines logcgiargs true usecookies true in the main system configuration file. Both options are false by default, so that no logging is done unless they are set. It is the logcgiargs line that actually turns logging on and off. By activating usecookies a unique identification code is assigned to each user, which enables individual user's interactions to be traced through the log file. Each line in the user log records a page visited—even the pages generated to inspect the log files! It contains (a) the IP address of the user's computer, (b) a timestamp in square brackets, (c) the CGI arguments in parentheses, and (d) the name of the user's browser (Netscape is called “Mozilla”). Here is a sample line, split and annotated for ease of reading: /fast-cgi-bin/niupepalibrary (a) its-www1.massey.ac.nz (b) [ Thu Dec07 23:47:00 NZDT2000] (c) (a=p, b=0, bcp=, beu=, c=niupepa, cc=, ccp=0, ccs=0, cl=, cm=, cq2=, d=, e=, er=, f=0, fc=1, gc=0, gg=text, gt=0, h=, h2=, hl=1, hp=, il=l, j=, j2=, k=1, ky=, l=en, m=50, n=, n2=, o=20, p=home, pw=, q=, q2=, r=1, s=0, sp=frameset, t=1, ua=, uan=, ug=, uma=listusers, umc=, umnpw1=, umnpw2=, umpw=, umug=, umun=, umus=, un=, us=invalid, v=0, w=w, x=0, z=130.123.128.4-950647871) (d) “Mozilla/4.08 [en] (Win95; I ;Nav)” The last CGI argument, “z”, is an identification code or “cookie” generated by the user's browser: it comprises the user's IP number followed by the timestamp when they first accessed the digital library. The log file usage.txt is placed in the etc directoryin the Greenstone file structure (see the Greenstone Digital Library Developer's Guide).When logging is enabled, every action by every user is logged. However, only the last 100 entries in the log file are displayed by the usage log link in Figure .

Greenstone incorporates an authentication scheme which can be used to control access to certain facilities. At the moment this is only used to restrict the people who are allowed to enter the Collectorand certain administration functions. If, for a particular collection, it were necessary to authenticate users before returning information to them, this is possible too—for example, documents could be protected on an individual basis so that they can only be accessed by registered users on presentation of a password. However, no current collections use this facility). Authentication is done by requesting a user name and password, as illustrated in Figure . From the administration page users can be listed, new ones added, and old ones deleted. The ability to do this is of course also protected: only users who have administrative privileges can add new users. It is also possible for each user to belong to different “groups”. At present, the only extant groups are “administrator” and “colbuilder”. Members of the first group can add and remove users, and change their groups. Members of the second can access the facilities described above to build new collections and alter (and delete) existing ones. When Greenstone is installed, there is one user called admin who belongs to both groups. The password for this user is set during the installation process. This user can create new names and passwords for users who belong just to the colbuilder group, which is the recommended way of giving other users the ability to build collections. User information is recorded in two databases that are placed in the Greenstone file structure (see the Greenstone Digital Library Developer's Guide).

The links under the Technical information heading show further information on the installation.The general link gives access to technical information, including the directories where things are stored.The protocols menu item gives, for each possible protocol type, information about each of the collections supported by that protocol. Finally, user interface code (called the “receptionist”) uses actions to communicate the wishes of the user. These actions correspond to the CGI argument labeled a. For example, if a=status the receptionist invokes the status action (which displays the status page). A menu item gives access to lists of all actions supported by the system, and another leads to the arguments that these actions take.