A couple years ago, RedHat Linux was a completely open-source, freely-available linux solution that brought linux to the masses. Then, RedHat changed the paradigm: they wanted to transform RHL to a corporate supported linux, and enjoined with the Fedora Project for community support. But now a choice had to be made for linux users-- stay with RedHat 9, purchase RedHat Enterprise Linux, or migrate to Fedora Linux.
But now, there are some new guys on the block, and one of them is CentOS -- the Community Enterprise OS. CentOS is not related to RedHat in any way -- what they do is take the open-source, freely-available RedHat Enterprise SRPMS (source RPMS), and make them available without the RedHat trademarks... all allowed under the terms of the licenses. CentOS allows members of the public to have an Enterprise-quality linux without the pressure to purchase it, or the obligation of signing a support contract.
CentOS may be found at http://www.centos.org. The website features articles about the organization, explains their licensing policy, and offers places for downloads. CentOS also sponsors support forums, although as a "linux", any questions that relate to linux can be found on the wild internet too.
CentOS is upgraded using the YUM (Yellowdog Updater Modified) utility. (I should note that YellowDog Linux may be thought of as "RedHat for Macintosh). There are archives all over the internet that may be accessed via yum, and it will solve the dependancy questions that are often encountered when adding a package.
CentOS comes with GNOME and KDE GUI interfaces available, although you are welcome to install anything written for Linux, and get it going. As OpenOffice2 is a recent release, CentOS 4.2 comes bundled with OO1.1, but I have upgraded it after the install using the RPM's at www.openoffice.org without any trouble. Other popular tools, such as Evolution, FireFox, Thunderbird, and VNC are included and ready to go.
Once you install CentOS, you may find yourself searching for a few updates and additional packages to complete your desktop environment. Due to the fuzziness of licenses and technology codecs, you will have to find your own DVD player software and codecs. That is easy to find, but companies like RedHat and CentOS do not distribute these packages with the OS, as it avoids legal pressures and lawsuits. Just do a search on "xine", install the things that you desire, and you can watch your movies, too!
CentOS comes with the common compiling tools and debuggers. You can download sources from places on the internet, and compile them, just like you can on a RedHat or Fedora box. CentOS also uses the RPM (RedHat Package Manager) if you are able to find your chose program in a distributed package. I have also compiled my own kernels using both the supplied code, along with "vanilla" kernels from www.kernels.org
The present version of CentOS is 4.2 -- the same revision level of RedHat's Enterprise Product -- and it features the 2.6.9-11 Kernel. CentOS 4.2 runs faster on my Pentium III 666 MHz than Fedora Core 4 did.
Check out CentOS. It's stable, it's good, and it's Linux.