Tars - TARS enables users to create chatbots that replaces regular old webforms.
Dialogflow - Conversational UX Platform. (ex API.ai)
Phonexia Voicebot Suite - Phonexia Voicebot Suite is an all-in-one voicebot-building solution for the rapid, on-premise development of highly sophisticated conversational AI interfaces for contact centers and other automated systems.
Octane AI - Octane AI offers tools to create a bot and engage customers and audience via messaging.
Botpress - Open-source platform for developers to build high-quality digital assistants
IBM Watson Assistant - Watson Assistant is an AI assistant for business.