Multiple OLSR implementations exist, but as of this writing, only three of the freely available implementations claim to be RFC3626 compliant: NRL olsrd[8], QOLSR[9] and UniK olsrd.
NRL olsrd is developed at the Naval Research Laboratory of the U.S. army. It is implemented in C++ and said to be RFC3626 compliant. Tests show that it is interoperable with the UniK implementation. Nrlolsrd is available for many platforms(Unix, OS X, Windows NT), however, it does not support multiple interfaces. As seen later, the multiple interface support is actually what prevents UniK olsrd form being ported to other platforms.
QOLSR is a C++ implementation of RFC3626 aimed at Quality of Service research for MANETS. This implementation is part of an ongoing project at Laboratoire de Recherche en Informatique in France. This implementation has not been tested with UniK olsrd.