After my 2nd article on Yum, you should be well prepared for using 3rd party repositories, so here is the list I currently use myself for CentOS 4:
1.) Dag’s repository is my favorite on this list. It contains well tested and stable software for CentOS 4. Famous examples are up-to-date versions of the mailreader pine, spamassassin and many perl modules.
2.) Dries repository is also very useful for some multimedia stuff like mplayer. It also contains some alternatives to the Apache webserver like thttpd and lighthttpd which some of you might find useful.
3.) Karan’s repository is a little special as it is the only 3rd party repository I know that is specialised on CentOS (of course all software there will perfectly run on RHEL as well). The next thing about Karan is that it provides two repositories: The first one is a rebuild of the Fedora Extras repository for CentOS. The second one provides misc packages that Karan has chosen to rebuild for CentOS.
4.) ATrmps repository is on the bleeding edge of many things, so be careful what you install from there. The “protect=0” flag is recommended for this repository (see here). On the other hand, you will find much useful stuff there like the latest 1.x branch of dovecot for example, a very secure and easy to configure IMAP and POP3 daemon. CentOS 4 only comes with the 0.99 version. In addition, you will also find many WLAN drivers and media center stuff there.
So, I am at the end with my coverage of Yum. If you still have any questions feel free to ask! Hope you enjoyed it. Now I gotta think of another theme to write about…Stay tuned ;-)