CrateDB is a distributed and scalable SQL database for storing and analyzing massive amounts of data in near real-time, even with complex queries. It is PostgreSQL-compatible, and based on Lucene.

converts binary PDF to JSON and text, for server-side PDF processing and command-line use. Zero dependency.

Content based and collaborative filtering based recommendation and personalization engine implementation on Hadoop and Storm

Stand-alone recommender system from Myrrix