Microsoft Bot Framework - Framework to build and connect intelligent bots.
Zendesk Answer Bot - Chatbots
Gomix - The easiest way to build the app or bot of your dreams
Aivo - Skyrocket your Customer Service and Sales KPIs with a Chatbot powered by Artificial Intelligence. Give time back to people.
BotList - An app store for bots
Tars - TARS enables users to create chatbots that replaces regular old webforms.