Alexa Skill Kit - Effortless Alexa Skill development with AWS Lambda
MessageBird Voice API - Add programmatic call capabilities to your app or service
BotTalk - Create Alexa skills and Google Assistant actions with Markup
MessageBird Chat API - Connect with your customers through different messaging apps
OK Google - Explore over 150 Google Now voice commands in one place
Voiceflow - Build voice apps in your browser without coding