Cassandra was open sourced by Facebook in 2008, but already the distributed database is being used by a number of major websites including Digg, Reddit, and Twitter. What began as a simple, lightweight database to store the tidbits of information sent to Facebook is now one of the first projects that architects consider. The system offers greater speed and automatic replication across nodes but only delivers "eventual consistency," something that would give a traditional DBA heart palpitations. Most of the latest websites trafficking in the social ephemera, though, happily accept the trade off because they don't require the accuracy of banks or airlines. And removing the need to be always accurate produces faster results.
License: Apache License 2.0
The Bossies 2010 index:
Bossie Awards 2010: The best open source software of the year
Bossie Awards 2010: The best open source applications
Bossie Awards 2010: The best open source application development software
Bossie Awards 2010: The best open source platforms and middleware
Bossie Awards 2010: The best open source networking software
