Mycroft.AI - Mycroft is the world’s first open source assistant.
VoiceAttack - VoiceAttack will take commands that you speak into your microphone
Rhasspy - Rhasspy transforms voice commands into JSON events that can trigger actions in home automation software.
VoiceMacro - Control applications or games by voice commands and/or by the press of a keyboard, mouse button or...
Google Assistant - Get things done with Google Assistant
SpeechTurtle - SpeechTurtle is a voice recognition tool that has a simplified c# scripting interface.