Open Source Favorite Links

I am running into open source stuff everyday and weeks down the road I am forgetting about a cool tool or software that I ran into. So I am thinking of creating this blog with links to all stuff related to open source. You are welcome to add your favorite links here. To start with yes of course my favorite linux distros:

Linux:
1. www.centos.org
2. www.ubuntu.org

Virtualization:
1. www.openvz.org
2. www.citrix.com/xenserver

Desktop virtualization:
1. www.virtualbox.org

Telephony:
1. www.asterisk.org
2. www.freepbx.org

CRM/ERP/ECM:
1. www.vtiger.org
2. xtuple.com
3. knowledgetree.com

CMS Systems:
1. www.drupal.org
2. www.joomla.org

Web and Mail:
1. www.apache.org
2. www.postfix.org
3. www.zimbra.com
3. www.dovecot.org
4. VSFtp
5. And many more in this category

Other Misc.

1. http://www.opensourcehelpdesklist.com/
2. www.dotproject.net
3. http://www.project.net/
4. www.aras.com <-- used in major automotive and aerospace indsutry
5. www.tutos.org <-- Team management used in a major truck mfg.