RoboRep - Create conversational chatbots with empathy
Octane AI - Octane AI offers tools to create a bot and engage customers and audience via messaging.
CSML Playground - Play with CSML, the programming language for chatbots
Dialogflow - Conversational UX Platform. (ex API.ai)
ChatBot - Easy to use chatbot platform for business
Botkit - Botkit is an open source developer tool for building chat bots, apps and custom integrations for major messaging platforms.