APIdoc - Inline Documentation for RESTful web APIs
swagger.io - Swagger is an open source RESTapi Documentation Tool.
Optic - Automate routine programming
Doxygen - Generate documentation from source code
ng-docx - Ng-docx is a library that automatically generates a documentation page to easily and beautifully view your markdowns.
MireDot - Miredot generates REST API documentation straight from your existing Java sources!