Google Duplex - An AI assisstant that can talk on the phone 🤖
Alexa Skill Kit - Effortless Alexa Skill development with AWS Lambda
Ringbot - Have a bot call someone and tell them your message!
BotTalk - Create Alexa skills and Google Assistant actions with Markup
OK Google - Explore over 150 Google Now voice commands in one place
Dialogflow - Conversational UX Platform. (ex API.ai)