Node.js

• vuepress - Minimalistic Vue-powered static site generator.
• jsdoc - An API documentation generator for JavaScript.
• dox - JavaScript documentation generator for node using markdown and jsdoc.
• docpress - Documentation website generator. Generates great websites from Markdown files.
• GitBook - Modern book format and toolchain using Git and Markdown.
• Flatdoc - Flatdoc is a small JavaScript file that fetches Markdown files and renders them as full pages.
• documentation - A documentation generation system that's beautiful by default, flexible across formats and styles, and powerful enough to support JSDoc's advanced syntax.
• Hexo - A fast, simple & powerful blog framework, powered by Node.js.
• gatsby - Blazing fast static site generator for React.

Python

• Sphinx - Sphinx is a tool that makes it easy to create intelligent and beautiful documentation, written by Georg Brandl and licensed under the BSD license.
• Pycco - Literate-style documentation generator.
• MkDocs - Project documentation with Markdown.

Ruby

• Jekyll - Jekyll is a simple, blog-aware, static site generator perfect for personal, project, or organization sites.
• nacos - Nanoc is a flexible static-site generator written in Ruby.

Go

• hugo - A Fast and Flexible Static Site Generator built with love in GoLang.

Rust

• mdBook - Create book from markdown files. Like Gitbook but implemented in Rust.
• zola - A fast static site generator in a single binary with everything built-in.