How do you usually do the processing of the messages? By using those services? Others? Maybe open-source libs? Or something coded something from scratch?
I already used LUIS.ai and IBM Watson.
They are pretty good to handle intents and entities.
If you want to use open source, I suggest you to start with NLTK lib for python.
So if you add to make a bot today, what would you use?
I use LUIS. It is similar to how wit does intent and entity classification.
LUIS.ai If I need to learn more from the users
Watson If it’s a close scope NLP. (few intents and some entities)
AIML or home made script If it’s a chatbot with diverse topics, that Watson or Luis can’t handle the intents with accuracy.