There is an explosion in database innovation right now I listed seven separate database platforms and tools that are exhibiting at the Open Source Convention. In addition to not listing Schooner Information Technology, I left out the elastic data solution provider:
Northscale They provide a couple key tools to assist you in managing your elastic data:memcached and membase open source technologies. Their servers are designed to work with existing relational database technology and expertise, and incrementally evolve toward a scale-out data architecture for use by web applications. They provide a developer kit to get you going.