Gus
Apple designed the Apple IIe Card to transition Apple IIe customers to the Macintosh LC, particularly schools who had a large investment in Apple II software. While Apple discussed creating an LC plug-in IIGS card, they felt that the cost of selling it would be as much as an entire LC and abandoned it. However, the educational community had a substantial investment in the IIGS software as well, which made upgrading to a Macintosh a less attractive proposition than had been for the Apple IIe. As a result, Apple software designers Dave Lyons and Andy Nicholas spearheaded a program to develop an IIGS software emulator they called Gus in their spare time, which would run on the Power Macintosh only. Apple did not officially support the project. Nevertheless, seeing the need to help switch their educational customers to the Macintosh (as well as sell Power Macs), Apple unofficially distributed the software for free to schools and institutions that signed a non-disclosure agreement. It was never offered for public sale, but is now readily available on the internet, along with many third party Apple II emulators. Gus represents one of the few software emulators developed within Apple (officially or not), including MacWorks and Mac OS X Classic environment.
Read more about this topic: Apple IIGS