wit.ai – Natural Language Service for Developers from Facebook
api.ai – Conversational User Experience Platform from Google. Build brand-unique, natural language interactions for bots, applications, services, and devices.
h2o.ai – H2O.ai is a Visionary in the Gartner Magic Quadrant for Data Science Platforms
Amazon Lex – Conversational interfaces for your applications. Powered by the same deep learning technologies as Alexa
Rasa NLU – Open-source language understanding for bots. A drop-in replacement for popular NLP tools like wit.ai, api.ai or LUIS
LUIS – Language Understanding Intelligent Service (LUIS). LUIS lets your app understand language