We have been working on the Spark cluster computing framework for last couple of years. It has always been open source under the BSD license in github. But yesterday Matei declared official launch of the spark website (spark-project.org) and mailing lists along with its 0.2 release to everyone during the AMPLab summer retreat at Chaminede, Santa Cruz.
Head over to the website to learn more about it, to download, and to solve real world problems (e.g., spam filtering, natural language processing and traffic estimation) lightning fast! It will get even better as more people use it and contribute back.