Wikipedia
OpenOSPFD
OpenOSPFD is an ISC licensed implementation of the Open Shortest Path First Protocol. It is a network routing software suite which allows ordinary general purpose computers to be used as routers exchanging routes with other computer systems speaking the OSPF protocol.
OpenOSPFD was developed by Esben Nørby and Claudio Jeker, for the OpenBSD project. It is a companion daemon of OpenBGPD. The software was developed as an alternative to packages such as Quagga, a routing software suite which is licensed under the GPL. OpenOSPFD is developed on OpenBSD, and ports exist for FreeBSD and NetBSD.