From the passage provided, extract the month and year when Cassandra was released on Google code
Avinash Lakshman, one of the authors of Amazon's Dynamo, and Prashant Malik initially developed Cassandra at Facebook to power the Facebook inbox search feature. Facebook released Cassandra as an open-source project on Google code in July 2008. In March 2009, it became an Apache Incubator project. On February 17, 2010, it graduated to a top-level project.

Facebook developers named their database after the Trojan mythological prophet Cassandra, with classical allusions to a curse on an oracle.
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Facebook released Cassandra as an open-source project on Google code in July 2008.
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