With release 5, CC died and was reborn as ClearFoundation.  ClearFoundation releases ClearOS.  ClearOS is the same as CC (with all the same developers), but they've reorganized to be a more appropriate open-source entity?  I'm not exactly clear on the change, but I can see some fragmentation -- now there's ClearOS (the software), ClearSDN (the services/licensing), and ClearFoundation (the organization).

Anyhow, I fell in love with CC for a few reasons, and those still apply to Clear.  With many linux-based firewall solutions, different VARs create sales channels by inventing their own applications to solve standard problems.  They furthermore close the box for you, often making their projects as difficult as possible to expand with standard methods.  These are the two primary reasons why I love clear: 1) Clear doesn't re-invent the wheel; ClearOS packages existing and proven open-source projects into their releases.  For example: Clear uses snort for IDS, DansGuardian for content-filtering, and samba for windows PDC/file sharing.  Clear takes these projects and wraps them up into one consistent and easy web-based GUI.  2) Clear encourages extending their platform.  In the CC days, you'd install cc-devel to get a compiler and development libraries.  Now with Clear, you just: yum groupinstall "Development Tools"

Once you satisfy dependencies, you can have ClearOS running as a Primary Domain Controller, awesome firewall, then throw in asterisk PBX, Zabbix distributed monitoring, and WHAMMO!  You've got one heck of a kick-ass border device!

Here's the download page: http://www.clearfoundation.com/Software/downloads

In the subpages, I'll outline some more specifics.  Also watch out for sub-subpages, which don't show up on the left.

2012-12:

After many happy years deploying and using this project, I am expecting to abandon it.  Read why in the zentyal section.