Kaldi

Written in C++, Kaldi has been a foundation of automatic speech recognition research and production systems for well over a decade. The toolkit provides the building blocks for complete recognition pipelines: feature extraction, acoustic modeling spanning GMM and neural network approaches, and decoding based on finite state transducers through OpenFst, with linear algebra handled by LAPACK, OpenBLAS, or ATLAS. Extensive example recipes for standard corpora ship in the repository and have served as starting points for many research papers and commercial systems. Kaldi runs on Linux, macOS, Cygwin, and Windows, and can be cross compiled for Android and WebAssembly. It predates the current wave of end to end speech models and demands more setup and expertise than pip installable alternatives, but remains in active use across academia, industry, and teaching. Released under the Apache 2.0 license.