There have been a few approaches to make sharing and consuming Web Services easier over the years. Many developers have worked with WSDL and SOAP services, as they were extremely popular in the early 2000’s and the beginnings of the .NET Framework. However, everything has moved on to being REST based and using JSON these days. This is a huge difference, and web service discoverability and sharing has needed to change in big ways as well. Swagger.io is a project that helps make RESTful APIs more easily sharable, discoverable, and self-documenting. Plus, Swagger is cross-platform and supports every popular programming language/framework.
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.