Scalaris is a scalable, transactional, distributed key-value store. It can be used for building scalable Web 2.0 services.
Scalaris uses a structured overlay with a non-blocking Paxos commit protocol for transaction processing with strong consistency over replicas. Scalaris is implemented in Erlang.
The Scalaris project was initiated by Zuse Institute Berlin and onScale solutions GmbH and is partly funded by the EU projects Selfman and XtreemOS. More information (papers, videos) can be found at http://www.zib.de/CSR/Projects/scalaris and http://www.onscale.de/scalaris.html.