Swagger is an open source RESTapi Documentation Tool.
- - swagger.io is the most popular Web-based, Windows, Mac & Linux alternative to APIdoc.
- - swagger.io is the most popular Open Source & free alternative to APIdoc.
The last version (3.2.2) is from January 2019.
aglio - An API Blueprint renderer that supports multiple themes and outputs static HTML that can be served by any web host. API Blueprint is a Markdown-based document format that lets you write API descriptions and documentation in a simple and straightforward way.
Optic is an open-source tool that automatically documents and tests your API. It makes it easy to keep your API specification and code in sync and automates your contract testing.
- - Optic is the most popular SaaS alternative to APIdoc.
Building APIs redefined. Speed up development of services, mobile, and web applications with auto-generated client, server, and documentation in many languages. Cut the costs and development time by up to 50%.