The VoltDB team have announced the general availability of Volt. Volt is supposed to be an in-memory relational DBMS using standard SQL as its language and standard transactional integrity as its data model, which is rather refreshing amongst all the hubbub nowadays about NoSQL, Key/Value stores, and so forth.
Volt can't really seem to decide what sort of organization they are, however. Part of the company seems to want to be an open-source company, and they are making the source available via Subversion and licensing it under GPLv3. But another part of the company seems to want to be a traditional enterprise software startup: the website trumpets their "serial entrepreneur" leadership and their "technical overview" links lead to a marketing page that asks you to register as a sales lead to get the information. The best information about the VoltDB architecture appears to be this paper from VLDB 2008.
It's very interesting that their stored procedure language is Java. In the Derby community, we have fairly extensive experience with using Java as a server-side stored procedure language. I wonder if the Volt community is interested in sharing their experiences with the Derby community?