Unnamed Angband is a variant of Angband (thangorodrim.angband.org), a free rogue-like computer game available on multiple platforms.

From the readme.txt:
Unnamed Angband adds over 100 class/style combinations to Angband, 130 new spells, 60 new spell books and spell related objects, over 500 new monsters, 196 features, 230 room descriptions and slightly modifies combat and monster spell casting.

These numbers are now very out of date.