ClearOS - Linux based Operating System

ClearOS is a powerful network and gateway server designed for small organizations and distributed environments. The open source revolution in the software industry has made it possible to provide ClearOS at no cost. Among other features, antivirus, antispam, VPN and content filtering are built right into the software -- no need for expensive third party add-ons. With ClearOS, you can avoid costly vendor lock-in and proprietary formats; instead, you can embrace open standards and protocols. Its feature include:

• Integrated LDAP for User and Group Management
• User Security Certificate Manager
• Multi-WAN, VPN - PPTP, IPsec, OpenVPN, DMZ and 1-to-1 NAT, Firewall, Local DHCP and DNS Servers
• Bandwidth Management
• Intrusion Protection, Intrusion Prevention, Intrusion Detection
• Antimalware - Antivirus, Antiphishing, Antispyware, Antispam
• Protocol Filtering including Peer-to-Peer Detection
• Content Filter
• Web Proxy
• Access Control
• File and Print Services
• Mail Server - POP, IMAP, SMTP, Webmail, Retrieval, Archiving
• Database with MySQL
• Web Server with PHP Support