Deepgram - Search engine for speech
Jasper - Jasper is an open source platform for developing always-on, voice-controlled applications.
Cassette - Transcribe, record & share conversations
Speechmatics - The most accurate and inclusive speech-to-text API ever released.
Hidden Markov Model Toolkit - Hidden Markov Model Toolkit (HTK) is a portable toolkit used for speech recognition research, speech synthesis, character recognition and DNA sequencing.
Scale - Get human tasks done with just one line of code.