CompileIt! is a HyperCard stack that compiles HyperTalk into 68K code. It's mainly used for writing HyperCard XCMDs and XFCNs, but can be used for other applications as well. (PowerFPU was written using CompileIt).
See also: Double-XX
Requires HyperCard. Inside the .zip there are three .sit files, one for each floppy disk.