Not only Microsoft is using open source technology for Kumo—their new search technology and Nth Google Killer—but they are giving back to the community:
Instead of creating a proprietary copy of these pieces of infrastructure, Powerset decided instead to turn to Hadoop, a Lucene subproject that is a framework for running data-intensive applications on large clusters of commodity hardware...Unfortunately, there was no Hadoop equivalent to Google's BigTable storage engine.
Because we have benefited greatly by leveraging the available Hadoop technology, Powerset decided to give back to the community by developing an open-source analogue to BigTable that is built on top of HDFS (Hadoop Distributed File System). After all, we need to develop it, anyway, it isn't part of the Powerset "secret sauce," and we, in turn, could benefit from contributions from other members of the community.
In other news, Satan called. He said the snow in hell is great but it's freezing down there, so bring your skis and a big coat. [Cnet]