SimpleServer is a Perl module which is intended to make it as simple as
possible to develop new Z39.50 servers over any type of database
imaginable.  All you have to do is implement a function for initialising your
database (optional), searching the database, and returning "database
records" on request.  The module takes care of everything else and
automatically starts a server for you, listens to incoming connections,
and implements the Z39.50 protocol.  It couldn't really be easier.

SimpleServer is based on the popular YAZ toolkit which means it is
robust, efficient, widely portable, and it interoperates with all known
Z39.50 clients.

Use SimpleServer together with other Perl modules to provide gateways
to relational databases, local file stores, SOAP/RDF-servers, etc.

SimpleServer currently supports the Init, Search, Present, Scan and
Close services.

WWW: http://www.indexdata.dk/simpleserver/