Lapsus Calumni is the title of M.S. Jackson’s internet fanzine and its accompanying blog. His more recent fanzine issues contained great material for Warrior, Rogue & Mage.
Each of these fanzine issues (in PPDF format) contain a short story as introduction, and some high quality roleplaying material. In the case of Goblyn Grotto you get a map of aforementioned grotto and stats for several monsters compatible with WR&M.
I have to admit, I haven’t checked out his non-WR&M issues yet, but I am very impressed by what I’ve seen so far. He has also written an in-depth playtest report of WR&M, which you really should check out!