Apache is a free and open-source cross-platform web server software.
Debian is a Linux software which is a free open-source software.
Google Hosted Libraries is a stable, reliable, high-speed, globally available content distribution network for the most popular, open-source JavaScript libraries.
jQuery is a JavaScript library which is a free, open-source software designed to simplify HTML DOM tree traversal and manipulation, as well as event handling, CSS animation, and Ajax.
MathJax is a cross-browser JavaScript library that displays mathematical notation in web browsers, using MathML, LaTeX and ASCIIMathML markup.
Phusion Passenger is a free web server and application server with support for Ruby, Python and Node.js.
Redmine is a free and open-source, web-based project management and issue tracking tool.
Ruby on Rails is a server-side web application framework written in Ruby under the MIT License.