Okapi is a library of Machine Learning and graph mining algorithms for Giraph. The library includes state-of-the-art Collaborative Filtering algorithms used in recommendation systems as well as graph algorithms such as partitioning, clustering and sybil-detection for OSNs.
The Okapi library is developed by the Telefonica Research lab and is available as open source under the Apache License. Users are invited to contribute to the library, to make it more robust and rich in features. Okapi is part of the Grafos.ML project.