Dialogflow - Conversational UX Platform. (ex API.ai)
Alexa Skill Kit - Effortless Alexa Skill development with AWS Lambda
Telegram - Telegram is a messaging app with a focus on speed and security. It’s superfast, simple and free.
Jovo - 🗣 Build cross-platform apps for Alexa and Google Home
Botpress - Open-source platform for developers to build high-quality digital assistants
Voiceflow - Build voice apps in your browser without coding