Swagger : Swagger is a powerful open source framework backed by a large ecosystem of tools that helps you design, build, document, and consume your RESTful APIs...
Mapstraction : A javascript library to hide differences between mapping APIs.
Hoppscotch : A free, online, open source API request builder
Freebase : A community-curated database of well-known people, places, and things
Eve : Eve is an open source Python REST API framework designed for human beings. It allows to effortlessly build and deploy highly customizable, fully featu...
Bluepine is a DSL for defining API Schema/Endpoint with the capabilities to generate Open API (v3) spec, validate API request and serialize object for API response based on single schema definition.