Mycroft.AI - Mycroft is the world’s first open source assistant.
SEPIA Framework - SEPIA is a server-based, extendable, personal, intelligent assistant.
Rhasspy - Rhasspy transforms voice commands into JSON events that can trigger actions in home automation software.
Google Assistant - Get things done with Google Assistant
Jasper - Jasper is an open source platform for developing always-on, voice-controlled applications.
Amazon Alexa - Virtual assistant developed by Amazon