From PCGamingWiki, the wiki about fixing PC games
Inform began as a reverse-engineered version of
Games made in Inform are not playable on their own; instead, Inform generates story files which must be opened with an interpreter.
- Gargoyle is a popular multi-platform interpreter which can play both Z-code and Glulx games as well as games made in other interactive fiction authoring systems. A comprehensive list of interpreters which can play Inform games can be found at the IF Archive under interpreters-multi, interpreters-glulx, and interpreters-infocom-zcode (some downloads may be out of date). Inform can be used to make games in either of two formats: Z-code (usually .zblorb, .z5, or .z8) and Glulx (usually .gblorb or .ulx). Some interpreters can play both, while others can only play one or the other.