+This is a listing of some of the most important features of the
+system.
+
+<itemize>
+
+<item>
+Supports updating - records can be added and deleted without
+rebuilding the index.
+
+<item>
+Supports large databases - files for indices, etc. can be
+automatically partitioned over multiple disks.
+
+<item>
+Supports arbitrarily complex records - base input format is an
+SGML-like syntax which allows nested (structured) data elements, as
+well as variant forms of data.
+
+<item>
+Supports boolean queries as well as relevance-ranking (free-text)
+searching. Right truncation and masking in terms are supported, as
+well as full regular expressions.
+
+<item>
+Supports multiple concrete syntaxes
+for record exchange (depending on the configuration): GRS-1, SUTRS,
+ISO2709 (*MARC). Records can be mapped between record syntaxes and
+schema on the fly.
+
+<item>
+Protocol support:
+
+<itemize>
+
+<item>
+Protocol facilities: Init, Search, Retrieve, Browse.
+
+<item>
+Piggy-backed presents are honored in the search-request.
+
+<item>
+Named result sets are supported.
+
+<item>
+Easily configured to support different application profiles, with
+tables for attribute sets, tag sets, and abstract syntaxes.
+Additional tables control facilities such as element mappings to
+different schema (eg., GILS-to-USMARC).
+
+<item>
+Complex composition specifications using Espec-1 are partially
+supported (simple element requests only).
+
+<item>
+Element Set Names are established the Espec-1 capability of the
+system, and are given in configuration files as simple element
+requests (and possibly variant requests).
+
+<item>
+Some variant support (not fully implemented yet).
+
+<item>
+Using the YAZ toolkit for the protocol implementation, the
+server can utilise a plug-in XTI/mOSI implementation (not included) to
+provide SR services over an OSI stack, as well as Z39.50 over TCP/IP.
+
+</itemize>
+
+</itemize>
+
+<sect1>Future Work
+
+<p>
+This is an early alfa-release of the software, to allow you to look at
+it - try it out, and assess whether it can be of use to you. We expect
+this version to be followed by a succession of beta-releases until we
+arrive at a stable first version.
+
+These are some of the plans that we have for the software in the near
+and far future, approximately ordered after their relative importance.
+Items marked with an
+asterisk will be implemented before the
+last beta release.
+
+<itemize>
+
+<item>
+*Allow the system to handle additional input formats. Specifically
+MARC records and general, structured ASCII records (such as mail/news
+files) parameterized by regular expressions.
+
+<item>
+*Complete the support for variants. Finalize support for the WAIS
+retrieval methodology.
+
+<item>
+*Finalize the data element <it/include/ facility to support multimedia
+data elements in records.
+
+<item>
+*Port the system to Windows NT.
+
+<item>
+Add robust database updating - tolerant to crashes or hard interrupts
+during register updating.
+
+<item>
+Add online updating, to permit register updating while users are
+accessing the system.
+
+<item>
+Add index and data compression to save disk space.
+
+<item>
+Add more sophisticated relevance ranking mechanisms. Add support for soundex
+and stemming. Add relevance feedback support.
+
+<item>
+Add Explain support.
+
+<item>
+Add support for very large records by implementing segmentation and
+variant pieces.
+
+<item>
+Support the Item Update extended service of the protocol.
+
+<item>
+The Zebra search engine supports approximate string matching in the
+index. We'd like to find a way to support and control this from RPN.
+
+</itemize>
+
+Programmers thrive on user feedback. If you are interested in a facility that
+you don't see mentioned here, or if there's something you think we
+could do better, please drop us a mail. If you think it's all really
+neat, you're of course welcome to drop us a line saying that, too.
+<sect>Introduction
+
+<sect>Compiling the software
+
+<p>
+Zebra uses the YAZ package to implement Z39.50, so you
+have to compile YAZ before going further. Specifically, Zebra uses