CMU Sphinx, also called Sphinx in short, is the general term to describe a group of speech recognition systems developed at Carnegie Mellon University. CMU Sphinx is a set of speech recognition development libraries and tools that can be linked in to speech-enable applications. The libraries and sample code. Speech and Language projects and groups at Carnegie Mellon University CMU Sphinx open source/free software speech recognition/acoustic model training.
PocketSphinx is a lightweight speech recognition engine, specifically tuned for handheld and mobile devices, though it works equally well on the desktop.