CMU Sphinx: Project by Carnegie Mellon University

Project Website:

Github Link:

Description

CMUSphinx collects over 20 years of the CMU research. All advantages are hard to list, but just to name a few:

State of art speech recognition algorithms for efficient speech recognition. CMUSphinx tools are designed specifically for low-resource platforms
Flexible design
Focus on practical application development and not on research
Support for several languages like US English, UK English, French, Mandarin, German, Dutch, Russian and ability to build a models for others
BSD-like license which allows commercial distribution
Commercial support
Active development and release schedule
Active community (more than 400 users on Linkedin CMUSphinx group)
Wide range of tools for many speech-recognition related purposes (keyword spotting, alignment, pronuncation evaluation)