Xandros Desktop OS Version 3
 

Xandros Business Desktop OS is the secure, easy-to-use, and compatible alternative to Windows for any size organization. Built on a solid Debian/GNU Linux foundation, the Xandros Business Desktop OS is engineered from the ground up to integrate seamlessly with existing enterprise environments, where security, compatibility, and ease of use are essential requirements.

Windows 2000/2003 Active Directory server and Windows NT PDC authentication

Drag-and-drop CD and data DVD burning in Xandros File Manager
Run MS Office and other key Windows programs
Seamlessly share files on Windows networks
Encrypted home folders, personal firewall, PPTP VPN client, antivirus
Multi-processor (SMP), and Hyper-Threading support

http://www.xandros.com/index.html