- <section>
- <title>Overview</title>
- <para>
- <ulink url="http://indexdata.dk/metaproxy/">Metaproxy</ulink>
- is a standalone program that acts as a universal router, proxy and
- encapsulated metasearcher for information retrieval protocols such
- as Z39.50 and SRU/SRW. To clients, it acts as a server of these
- protocols: it can be searched, records can be retrieved from it,
- etc. To servers, it acts as a client: it searches in them,
- retrieves records from them, etc. it satisfies its clients'
- requests by transforming them, multiplexing them, forwarding them
- on to zero or more servers, merging the results, transforming
- them, and delivering them back to the client.
- </para>
- <para>
- Metaproxy is a more capable alternative to
- <ulink url="http://indexdata.dk/yazproxy/">YAZ Proxy</ulink>,
- being more powerful, flexible, configurable and extensible. Among
- its many advantages over the older, more pedestrian work are
- support for multiplexing (encapsulated metasearching), routing by
- database name, authentication and authorisation and serving local
- files via HTTP. Equally significant, its modular architecture
- facilitites the creation of pluggable modules implementing further
- functionality.
- </para>
- </section>
+ <para>
+ <ulink url="&url.metaproxy;">Metaproxy</ulink>
+ is a standalone program that acts as a universal router, proxy and
+ encapsulated metasearcher for information retrieval protocols such
+ as <ulink url="&url.z39.50;">Z39.50</ulink>, and in the future
+ <ulink url="&url.sru;">SRU</ulink> and <ulink url="&url.srw;">SRW</ulink>.
+ To clients, it acts as a server of these protocols: it can be searched,
+ records can be retrieved from it, etc.
+ To servers, it acts as a client: it searches in them,
+ retrieves records from them, etc. it satisfies its clients'
+ requests by transforming them, multiplexing them, forwarding them
+ on to zero or more servers, merging the results, transforming
+ them, and delivering them back to the client. In addition, it
+ acts as a simple <ulink url="&url.http;">HTTP</ulink> server; support
+ for further protocols can be added in a modular fashion, through the
+ creation of new filters.
+ </para>
+ <screen>
+ Anything goes in!
+ Anything goes out!
+ Cold bananas, fish, pyjamas,
+ Mutton, beef and trout!
+ - attributed to Cole Porter.
+ </screen>
+ <para>
+ Metaproxy is a more capable alternative to
+ <ulink url="&url.yazproxy;">YAZ Proxy</ulink>,
+ being more powerful, flexible, configurable and extensible. Among
+ its many advantages over the older, more pedestrian work are
+ support for multiplexing (encapsulated metasearching), routing by
+ database name, authentication and authorisation and serving local
+ files via HTTP. Equally significant, its modular architecture
+ facilitites the creation of pluggable modules implementing further
+ functionality.
+ </para>
+ <para>
+ This manual will briefly describe Metaproxy's licensing situation
+ before giving an overview of its architecture, then discussing the
+ key concept of a filter in some depth and giving an overview of
+ the various filter types, then discussing the configuration file
+ format. After this come several optional chapters which may be
+ freely skipped: a detailed discussion of virtual databases and
+ multi-database searching, some notes on writing extensions
+ (additional filter types) and a high-level description of the
+ source code. Finally comes the reference guide, which contains
+ instructions for invoking the <command>metaproxy</command>
+ program, and detailed information on each type of filter,
+ including examples.
+ </para>