PD "clone" of (1) nroff (2) spell wanted

[Steve Rudek]

I'd appreciate any leads on public domain clones of "nroff" and "spell."
Microport, like an increasing number of vendors, sells the "text formatting"
programs as an option.  That's generally okay with me; I regard a Mac as the
only way to go when doing fancy documents.  However, the lack of two programs
-- "nroff" and "spell" -- does pain me.  In particular, I wish I had  nroff.
So many of the sources posted to the net include an "nroff"ed man page.
I really don't even care about printing nroffed documents; I just want
to be able to read them on my terminal.  The "deroff" program which comes with
Microport leaves a mess and has a tendancy to delete important text in the
process of removing nroff codes. 
 
I believe that _Dr. Dobb's_ published an nroff clone some time back, but
I don't know how exact a clone it was and, in particular, I don't think it
supported terminal output.  Have the GNU folks possibly been working on
a clone?  I've never used nroff so I've only a general idea what I'm asking
for.