Use LensKit to build your next recommender application.


Use LensKit to research recommender algorithms, evaluation techniques, or user experience.

Get LensKit

Learn about LensKit

Connect with LensKit


LensKit is free and open-source software, available under the terms of the GNU Lesser General Public license version 2.1 or later.


LensKit is developed primarily by researchers at Texas State University and GroupLens Research at the University of Minnesota, with contributions from developers around the world. It is made possible by support from a number of organizations:

  • Multiple GroupLens Research projects, particularly MovieLens and BookLens, use LensKit in production, providing experience, bug reports, and other valuable feedback (and code). We also maintain list of LensKit users.
  • Development has been funded in part by the National Science foundation (under grants IIS 05-34939, 08-08692, 08-12148, and 10-17697).
  • YourKit is kindly supporting the project with free licenses for the YourKit Java profiler.