StyleDocco : StyleDocco generates documentation and style guide documents from your stylesheets.
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...
HTML2PDF : HTML2PDF is a HTML to PDF converter written in PHP.
It allows the conversion of valid HTML 4.01 in PDF format, and is distributed under OSL.
phpDocumentor enables you to generate documentation from your PHP source code. This documentation provides an in-depth view of your project to you, your consumers and contributors.