Unlike the hobbyist nature of White Box Linux, CentOS is more of a full-time effort from a dedicated non-profit foundation. CentOS 3.3 is supposed to be the equivalent of RHEL3.
I installed CentOS 3.3 on an AMD Athlon 2400 XP server with an MSI KM400AM Motherboard (VIA chipset), 512MB DDR-RAM, 120GB SATA and 80GB PATA hard drives, and Nvidia GeForce 2 display adapter. The installation is the standard Red Hat-esque installation. I was happy and mildly surprised to find it supported my SATA controller. The installation was easy and problem-free, and took 15 minutes from bootup to the first run wizard.
Like Red Hat, CentOS has a first run wizard where you create a user, check your time zone and sound card, and can install documentation if you have any additional CDs. CentOS does not offer any additional CDs, so this option is moot.
After the first run wizard, CentOS booted into a desktop identical to Red Hat's, except for the different-looking start button. A minute after loading the desktop, a red exclamation appeared in the task bar. I clicked it, which started the CentOS update agent, which is identical to the Red Hat agent and does the same job. It showed 683 updates available for my installation. I started the download, and ran into a bug. Almost all the packages popped up a warning about being wrongly signed, and the program required me to click "yes" before it would continue -- very irritating. After downloading all the updates, the icon still showed me 683 updates remaining. After I rebooted it showed no updates, so I suppose it was a question of refreshing something.
I emailed the CentOS folks about how quickly they update their packages, and Greg Kurtzer, the foundation head, had this to say.
For CentOS, we track the Red Hat updates as closely and quickly as possible. Typically we release our updates within hours of Red Hat's, but we publicize a 24-hour lead time. We have multiple people that have access to update the mirrors, so the team itself has the capability to consistently release updates quickly.
CentOS is marketed as not just a server OS, but as a workstation OS also, but surprisingly, it does not include any office suite. Surely a workstation distro should include OpenOffice.org or KOffice? Yes, downloading and installing these packages is not very difficult on a broadband connection, but these are essentials in an office workstation. A pure server OS may not need these, but if CentOS is being marketed as a workstation OS, they should be included. I asked the developers about this and they said that the RPMs are, in fact, on the CDs, but a bug in the comps.xml prevents the installer from showing them.
Besides the lack of an office suite, CentOS also lacks a good IDE and a Web site editor. In other words, if you want to get productive on CentOS as a workstation, you'll have to download and install a lot of software.
As a server, CentOS is a good replacement for RHEL. It is compatible with all RHEL software, and the CentOS team is very quick with updates. I set up my machine as a Web and DHCP server and it was exactly like Red Hat. The best part of using a RHEL clone is that all your Red Hat knowledge does not go to waste, and all the accumulated Red Hat information available on the Web and in books can be applied to CentOS without changing a thing. This makes CentOS easy to administer.
The high point of CentOS is the quick and easy updates. Its main flaw was the lack of some essential software packages. All in all, CentOS makes for a good server OS, and with some work, it can be a good workstation OS as well, though workstation users might be better off with Fedora. The organization behind CentOS, the cAos Foundation, is more than a one-man outfit, so there is a higher degree of assurance about CentOS. I hope that the developers fix the up2date and OpenOffice bug.