Drizzle: A High-Performance Microkernel DBMS for Scale-Out Applications
Drizzle is a community-driven project based on the popular MySQL DBMS that is focused on MySQL's original goals of ease-of-use, reliability and performance.
The Drizzle team is removing non-essential code, refactoring the remaining code, switching to a microkernel architecture (with well-defined APIs) and generally making Drizzle into a lean, mean query-running machine.
Participation is easy and fun. The Drizzle project is run using open source software (like Bazaar) on open and public resources (like http://launchpad.net/drizzle and irc://irc.freenode.net/#drizzle and wikia) in a true open source fashion. The Drizzle project also has clear guidelines for participation, as well as simple guidelines for licensing and use.
Drizzle is currently in alpha, with no stable release or binary and with major new changes being introduced daily.