BotList - An app store for bots
Octane AI - Octane AI offers tools to create a bot and engage customers and audience via messaging.
ManyChat - ManyChat lets you create a Facebook Messenger bot for marketing, sales and support.
Dialogflow - Conversational UX Platform. (ex API.ai)
Chatbot Templates - 50+ bot templates you can use in one click
Botkit - Botkit is an open source developer tool for building chat bots, apps and custom integrations for major messaging platforms.