The Infocom Bugs List
The Infocom Bugs List is a collection of errors and unexpected outcomes in Infocom games, originated by C.E. Forman (published in XYZZYnews) and later updated by others (notably Graeme Cree). Because of the full-sentence parser and object-oriented nature of ZIL, bugs involving the environments in the games are particularly entertaining. Many bugs are inherent to specific revisions of Infocom games, fixed in later production runs.
Warning: Many of the bugs are, in their description, spoilers in nature.