According to some metrics, Ubuntu is the most popular Linux distribution. See Installed base section.
Development of Ubuntu is led by Canonical Ltd., a company based in the Isle of Man and owned by South African entrepreneur Mark Shuttleworth. Canonical generates revenue through the sale of technical support and other services related to Ubuntu. According to Canonical, the Ubuntu project is committed to the principles of open source development; people are encouraged to use free software, study how it works, improve upon it, and distribute it.
Ubuntu is a fork of Debian's codebase, created to be an easy-to-use Linux desktop. Ubuntu's team commited to release predictably - every six months - and that each release would receive free support for nine months (eighteen months prior to 13.04) with security fixes, other high-impact bug fixes and very conservative, substantially beneficial low-risk bug fixes. The first release was on October 2004.
It was decided that every fourth release, issued on a two-year basis, would receive long-term support (LTS) Long term support includes updates for new hardware, security patches and updates to the 'Ubuntu stack' (cloud computing infrastructure).The first LTS releases were supported for three years on the desktop and five years on the server; since Ubuntu 12.04 LTS, desktop support for LTS releases was increased to five years as well. LTS releases get regular point releases with support for new hardware and integration of all the updates published in that series to date.
Ubuntu packages are based on packages from Debian's unstable branch: both