[OT]

Cawf is a suitable replacement for nroff (http://pkgsrc.se/textproc/cawf ). There is a current port of Cawf available from Hobbes: http://hobbes.nmsu.edu/h-search.php?key=cawf410&pushbutton=Search .

[somewhat closer to topic]

From a porting standpoint, building something basic - such as nroff - would be a good exercise. I am constantly trying to port things which are too complex to get done in a reasonable amount of time. I then run into issues, and get frustrated with the whole thing.