Chatfuel - Chatfuel is the best bot platform for creating an AI chatbot on Facebook.
BotList - An app store for bots
BotStar - BotStar | Engage Customers Online with Live Chat & Chatbots
ManyChat - ManyChat lets you create a Facebook Messenger bot for marketing, sales and support.
Telegram bot API - The Bot API allows you to easily create programs that use Telegram messages for an interface.
ChatBottle - Chatbots Search Engine