Tome 4's T-engine could fill that role easily if it were better documented.
Angband has all monsters, uniques, item types, ego-items, artefacts, races, classes, and a few other things defined in easy-to-edit text files, so many variants don't even have to recompile.
Ido's cryptrover is a good example of a minimalistic RL, in theory you could build a more complex game on top of that. The only problem is its makefile is overcomplicated (with optional sound and stuff) and invalid with some versions of make, so compiling is difficult.
And then there's the python/libtcod tutorial on roguebasin.
That's all that comes to mind at the moment.
Edit:
... *First* person? OK, forget the above.
