Vyatta - Free alternative to Cisco, Juniper, etc.

Vyatta is a high-end, open source software that installs on your own hardware and provides standard WAN (wide area network) routing protocols such as RIP (Routing Information Protocol), OSPFv2 (Open Shortest Path First version 2), and BGPv4 (Border Gateway Protocol version 4). It also includes intranet networking protocols such as DHCP (Dynamic Host Configuration Protocol), VRRP and SNMP. Vyatta Community edition is free to use and can be downloaded from here. Vyatta is available as a standalone installation, as a VMWare Virtual appliance, and as a Citrix Xenserver Image. Get to know more about Vyatta.