I just realized something on Google search:
linux - Google Search
1. The Linux Home Page at Linux Online
"Comprehensive information and resources about the Linux Operating System."
www.linux.org/
2. Ubuntu Linux
"Official site; Commercially sponsored Debian-derived Linux distribution that focuses on usability, a regular 6-month release cycle, and a commitment to at ..."
www.ubuntu.com/
3. Linux - Wikipedia, the free encyclopedia
"Linux refers to the family of Unix-like computer operating systems using the Linux kernel. Linux can be installed on a wide variety of computer hardware, ..."
en.wikipedia.org/wiki/Linux
4. Linux.com | The source for Linux information
"Linux.com - For the community, by the community, Linux.com is the central source for Linux information, software, documentation, how-tos and answers across ..."
www.linux.com/
5. redhat.com | The World's Open Source Leader
"Red Hat is the world's leading open source technology solutions provider with offerings including Red Hat Enterprise Linux, open source applications, ..."
www.redhat.com/
6. Debian GNU/Linux
"26 Jun 2010 ... Debian GNU/Linux is a free distribution of the GNU/Linux operating system. It is maintained and updated through the work of many users who ..."
www.debian.org/
7. DistroWatch.com: Put the fun back into computing. Use Linux, BSD.
"7 Sep 2010 ... News and feature lists of Linux and BSD distributions."
distrowatch.com/
8. Mandriva
"Mandriva (was MandrakeSoft) publishes Mandriva Linux distribution, designed, developed & packaged within the Mandriva Linux community."
www.mandriva.com/
9. Fedora Project
"Fedora is a Linux-based operating system that showcases the latest in free and open source software. Fedora is always free for anyone to use, modify, ..."
fedoraproject.org/
10. The Slackware Linux Project
"The original Linux distribution, geared towards power and stability. FAQ, support, news, mailing lists, downloads, and links."
www.slackware.com/
11. Gentoo Linux -- Gentoo Linux News
"The official pages for the distribution provide documentation, downloads and installation instructions, mailing-lists, forums, performance reviews and news."
www.gentoo.org/
12. The Linux Kernel Archives
"This is the primary site for the Linux kernel source."
www.kernel.org/
13. www.centos.org - The Community ENTerprise Operating System
"CentOS is an Enterprise-class Linux Distribution derived from sources freely provided to the public by a prominent North American Enterprise Linux vendor. ..."
www.centos.org/
14. openSUSE.org
"openSUSE is a free and Linux-based operating system for your PC, Laptop or Server. You can surf the web, manage your e-mails and photos, do office work, ..."
www.opensuse.org/
#14? There are eight other distros ahead of us. I wonder how many people stop at #5 or #6?