A drop-in replacement for the IRIX libfam library that can be built with GNU C++ compilers - and so avoids a breaking dependency on MIPSPro C++ libraries.
The sgug-fam library and source code come from the LGPL/GPL fam release made by SGI and available here:
https://cvs.savannah.nongnu.org/viewvc/fam/
Normally you'll get this as part of the sgug-rse project, go check there.