Linkedin and Twitter Contribute Machine Learning Libraries

In Infoq: Linkedin and Twitter contribute machine learning libraries.  " ... Twitter’s engineering group, known for various contributions to open source from streaming MapReduce to front-end framework Bootstrap recently announced open sourcing an algorithm that can efficiently recommend content. This is a really important problem for Twitter as it helps promoting the right ads to the right users and recommending which users to follow. The algorithm, named DIMSUM, can pre-process similarity data and feed the actual recommendation algorithm with a subset of users that are calculated to be above a similarity threshold. ...  "