This page is a portal to various resources concerning the new CQL
query language, on this site and elsewhere.
If you're not familiar with CQL, the best place to start is
probably with the
The formal specification for CQL, including a BNF grammar, is
held on the Z39.50 Maintenance Agency's CQL page at
(I've also taken a
of the Maintenance Agency's page, mostly so I can access it
when I'm not on-line.)
A presentation that I made to the IMS Query SIG in November
A proposal by Eliot, Rob, Sebastian and myself to allow CQL
profile more of the query language
- specifically relations and relation modifiers - so as to
allow a broad range of non-bibliographic applications yet to
This was accepted into mainstream CQL at the meeting of
25th-26th September 2003.
A nice, simple
for CQL, including a Bath Context Set.
announces the beta release of CQL-Ruby, a Ruby Gem that
implements a CQL parser. It is based on a translation of
CQL-Java, and serialises to SOLR rather than PQF.
The project site is