JSON Server vs rasa NLU: What are the differences?
JSON Server: Get a full fake REST API with zero coding in less than 30 seconds. For front-end developers who need a quick back-end for prototyping and mocking. Created with <3 for front-end developers who need a quick back-end for prototyping and mocking; rasa NLU: Open source, drop-in replacement for NLP tools like wit.ai. rasa NLU (Natural Language Understanding) is a tool for intent classification and entity extraction. You can think of rasa NLU as a set of high level APIs for building your own language parser using existing NLP and ML libraries.
JSON Server can be classified as a tool in the "API Tools" category, while rasa NLU is grouped under "NLP / Sentiment Analysis".
JSON Server and rasa NLU are both open source tools. It seems that JSON Server with 41.2K GitHub stars and 3.68K forks on GitHub has more adoption than rasa NLU with 5.76K GitHub stars and 1.7K GitHub forks.