Apart from being open source, what can other Conversational AI platforms (wit.ai, Lex, DialogFlow..) do that Rasa can't?
These are some of the main differences between Dialog Flow and Rasa:
Dialog Flow:
No installation needed, you can start using it immediately.
Easy to use, non-tech people can build a bot.
Closed system.
Web-based interface for building bots.
Data is hosted on the cloud.
Can’t be hosted on your server or on-premise.
Out-of-box integration with Google Assistant, Skype, Slack, Facebook Messenger, etc.
Rasa:
Requires installation of multiple components.
Requires tech knowledge.
Open-source code available in GitHub.
No interface provided, write JSON or markdown files.
No hosting provided.
You can host it on your server.
No out-of-box integration.