Considering the fact that MySQL is almost dead (and never was true open source database, especially for ISVs who wanted to bundle their apps with database engine), I would say that Firebird and PostgreSQL are the only open source databases of choice (and in my experience Firebird is much more suitable for bundling with Windows apps ).
It took only 10 years, and we now see Firebird as a choice in Evans Data Corp. survey:
I encourage all Firebird users and developers who use Firebird participate in this survey (it's open and free) and mark Firebird as their choice. It is very important for recognition of Firebird for newbie developers, journalists and other influencers.
