Mycroft.AI - Mycroft is the world’s first open source assistant.
TexTalky - Turn any text or script to a lifelike neural human voice, a powerful A.I text to speech realistic voiceover that covers more than 130 international languages & Accent and over 900 kinds of lifelike human voices that meets most of your needs.
Rhasspy - Rhasspy transforms voice commands into JSON events that can trigger actions in home automation software.
iSpeech - Implement speaking text feature to your app!
Google Assistant - Get things done with Google Assistant
Lyrebird - Copy the voice of anyone, using a voice imitation algorithm