Inform is a program that helps you write “interactive fiction,” a la Zork. (For you whippersnappers who’ve never heard of Zork, here’s the Wikipedia entry about it. Kids today, with your fancy-schmancy graphics and your abundance of CPU cycles. In my day, all we had were a brass lantern and an Elvish sword, and we couldn’t even see them.)
Uh, heh. Anyway, Inform. Maybe somebody with too much time on their hands can write an O*W*C-based adventure.