I thought I'd compile a list of Open Source software that I use and recommend

UPDATE: check out http://www.cleansoftware.org/internet/

Apache (web server)
http://httpd.apache.org

PHP (scripting language)
http://www.php.net

Drupal (Content Managment System) (100777.com is built on Drupal)
http://drupal.org

Gaim (IM client, AOL, ICQ, MSN, IRC, etc)
http://gaim.sourceforge.net

Azureus (Bittorrent client)
http://azureus.sourceforge.net

Firefox (web browser)
http://www.getfirefox.com

Thunderbird (mail/news client)
http://www.mozilla.org/projects/thunderbird/

Open Office (office suite)
http://www.openoffice.org

Gentoo Linux (operating system, quite advanced distribution)
http://www.gentoo.org

Ubuntu Linux (operating system, also for beginners)
http://ubuntulinux.org

Knoppix Linux (operating system, doesn't need installing, just burn on a CD and boot)
http://knoppix.org

Synergy
http://synergy2.sourceforge.net/