Decompiler
From IFWiki
A decompiler is the name given to a computer program that performs the reverse operation to that of a compiler. That is, it translates a file containing information at a relatively low level of abstraction (usually designed to be computer readable rather than human readable) into a form having a higher level of abstraction (usually designed to be human readable). In interactive fiction, this means taking a game file and changing it into a human readable source file--for instance, taking a z-code game and transforming it into Inform 6 code from which it could be compiled.
Links
- Interactive fiction decompilers - a summary created by Ben Rudiak-Gould.