Zendesk Answer Bot - Chatbots
Rasa Core - Rasa Core is a well-designed dialogue engine used to create chatbots.
Aivo - Skyrocket your Customer Service and Sales KPIs with a Chatbot powered by Artificial Intelligence. Give time back to people.
AWS Lambda + Motion AI - Build bots using Node.js, in your browser!
Tars - TARS enables users to create chatbots that replaces regular old webforms.
marbot - A Slack bot detecting and managing incidents on AWS.