is a very powerful and popular free open source full-text search engine. At the moment, Sphinx 2.2.11 is the last supported version.
Some years ago, Vlad Khorsun and Pierre Yager have made a patch for Sphinx, to have it supporting Firebird. Now, with the blessing of its author, Andrew Aksyonoff, they want to make their patch and Windows binaries publicly available for you to try out.
Whilst it is still far from real "full text search" support in Firebird, Vlad and Pierre believe it is a first little step in that direction. Deeply integrated Sphinx support can be added to Firebird later, probably using the external engines feature.
For now people can use Sphinx's FTS capabilities with Firebird databases using any existing Sphinx clients (for PHP, Ruby, C/C++ etc).