DesktopLinux.com published the results of their Desktop Linux Survey 2007

The leading Linux distribution is the Ubuntu family -- 30 percent of our survey respondents are using Ubuntu or one of its sister distributions: Kubuntu, Xubuntu, and Edubuntu. While there are other distributions that owe a great deal to Ubuntu -- Linspire, Freespire, MEPIS, Linux Mint, and Pioneer all come quickly to mind -- we decided not to count them for Ubuntu this year, since some, like Freespire, have just made the switch, while others, such as MEPIS, are switching back to Debian, and Pioneer is going in its own direction.

2007 Desktop Linux Survey results revealed