Angband itself also has dozens of forks[0], mostly bolting on additional mechanics like SAngband (skills Angband), or new content like ZAngband (Zelazny Angband), adding multiplayer like MAngband, all the way to an almost total rewrite to be more faithful to the Tolkien canon like Sil [1].

[0] http://www.roguebasin.com/index.php/List_of_Angband_variants

[1] https://www.amirrorclear.net/flowers/game/sil/