Vowpal Wabbit

Vowpal Wabbit (VW) is an extremely fast, scalable, and flexible open-source machine learning system designed for efficient out-of-core learning on large datasets. Sponsored by Microsoft Research, VW is suitable for researchers, data scientists, and developers needing advanced online learning and optimization techniques. It supports various optimization algorithms (such as sparse gradient descent), a powerful and flexible input format, and provides bindings for multiple languages in addition to a command line interface.