Postman : Save requests and organize your APIs into Collections. Create and send any HTTP request using the awesome Postman request builder. Write your own test...
Web Audio Studio : Visualize and debug Web Audio graphs
Write Web Audio API code and instantly see the graph it creates.
Inspect signal flow, tweak parameters, and hear ...
httpbin.org : A simple HTTP Request & Response Service.
pump.io : Social server with an ActivityStreams API. It's a stream server that does most of what people really want from a social network.
Mapstraction : A javascript library to hide differences between mapping APIs.
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.