Apache is a free and open-source cross-platform web server 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.
Twitter is a 'microblogging' system that allows you to send and receive short posts called tweets.
Ubuntu is a free and open-source operating system on Linux for the enterprise server, desktop, cloud, and IoT.