ClearOS 5.1 Enterprise Service Pack 1 CD, 1 disc set.

ClearOS (formerly ClarkConnect) is a network and gateway server designed for small businesses and distributed environments. Based on CentOS, a clone of Red Hat Enterprise Linux, the distribution includes an extensive list of features and integrated services which are easy to configure through an intuitive web-based interface. Some of the tools found in ClearOS include antivirus, antispam, VPN, content filtering, bandwidth manager, SSL certification, and web log analyser, just to name a few of the available modules. The distribution is provided as a free download, inclusive of free security updates for 18 months.

Note: This installation CD includes all the latest updates and bug fixes.

Link: http://www.clearfoundation.com/Software/overview.html