Currently, OpenFTS is "limited" to indexing/searching PostgreSQL databases. In other words OpenFTS uses PostgreSQL specific features/packages -- for example, the intarray package under contrib. At this point I can not say how much effort would be needed to port OpenFTS to other RDBMS. However, I can say that most of the code can be reused as it is. We have written a primer which explains how OpenFTS works and includes links to interesting/related research papers. It should be available soon at SourceForge. The project site is now public (
OpenFTS) but we have not upload the code yet.
