Ubuntu is a complete desktop Linux operating system, freely available with both community and professional support. The Ubuntu community is built on the ideas enshrined in the Ubuntu Manifesto: that software should be available free of charge, that software tools should be usable by people in their local language and despite any disabilities, and that people should have the freedom to customise and alter their software in whatever way they see fit. "Ubuntu" is an ancient African word, meaning "humanity to others". The Ubuntu distribution brings the spirit of Ubuntu to the software world.
Ubuntu 12.04 LTS (Long-Term Support). Code-named 'Precise Pangolin', 12.04 continues Ubuntu's proud tradition of integrating the latest and greatest open source technologies into a high-quality, easy-to-use Linux distribution. The team has been hard at work through this cycle, introducing a few new features and improving quality control. For PC users, Ubuntu 12.04 supports laptops, desktops, and netbooks with a unified look and feel based on an updated version of the desktop shell called 'Unity', which introduces 'Head-Up Display' search capabilities.
Project Website : http://www.ubuntu.com