ManyChat - ManyChat lets you create a Facebook Messenger bot for marketing, sales and support.
spaCy - spaCy is a library for advanced natural language processing in Python and Cython.
Chatfuel - Chatfuel is the best bot platform for creating an AI chatbot on Facebook.
Amazon Comprehend - Discover insights and relationships in text
ChatBot - Easy to use chatbot platform for business
Google Cloud Natural Language API - Natural language API using Google machine learning