> I can think of no obvious reason.

One of the reasons could be the full-text search, which MySQL has and
we don't... But I do not know if the search in MediaWiki uses FTS from
MySQL or they have implemented something themselves.

> Actually, mediawiki is already planning Firebird support:
> http://meta.wikimedia.org/wiki/MediaWiki_roadmap
> If you contact them, and offer help, it may get done quickly.

I agree, that would be the best possibility, since they know their
requirements better.

Roman