XORP is an open router platform.  XORP's primary goal is to be both
a research tool and a stable deployment platform.  It implements
routing protocols for IPv4 and IPv6 and a unified means to configure
them.

Currently, XORP implements the following protocols:
* OSPF v2 and v3
* RIP and RIPng
* BGP4
* PIM-SM
* IGMP v1, v2, and v3
* MLD v1 and v2
* OLSR
* VRRP

For documentation, see the XORP home page.