MkDocs is described as 'is static site generator that's geared towards building project documentation. Documentation source files are written in Markdown, and configured with a single YAML configuration file' and is a documentation generator in the development category. There are more than 25 alternatives to MkDocs for a variety of platforms, including Linux, Mac, Windows, Self-Hosted solutions and Online / Web-based. The best alternative is Wiki.js, which is both free and Open Source. Other great apps like MkDocs are GitBook, Read The Docs, Doxygen and Sphinx.
Write your content in the widely used and simple Markdown format, using the built-in visual editor. Unlike other wiki software that save content in a database with a difficult to extract format, Wiki.js saves all your content directly into Markdown (.
Read the Docs hosts documentation for the open source community. It supports Sphinx docs written with reStructuredText, and can pull from your Subversion, Bazaar, Git, and Mercurial repositories. The code is open source, and available on github.
Doxygen is a tool for generating documentation from annotated C++ sources, as well as other popular programming languages like C, Objective-C, C#, PHP, Java, Python, IDL (CORBA, Microsoft, and UNO/OpenOffice flavors), Fortran, VHDL, Tcl, and to some extent D.
Daux.io is a documentation generator that uses a simple folder structure and Markdown files to create custom documentation on the fly. It helps you create great looking documentation in a developer friendly way.
docsify generates your documentation website on the fly. Unlike GitBook, it does not generate static html files. Instead, it smartly loads and parses your Markdown files and displays them as website. All you need to do is create an index.