XORP is the eXtensible Open Router Platform.

Our goal is to develop an open source software router platform that is stable and fully featured enough for production use, and flexible and extensible enough to enable network research. Currenly XORP implements routing protocols for IPv4 and IPv6 and a unified means to configure them. In future, we would also like to support custom hardware and software forwarding architectures.

XORP is free. It is covered by a BSD-style license and is publicly available for research, development, and use.