(updated November 28, 2010)
FUSION is a free, closed-source emulator of 680×0 based Macintosh machines. It's a DOS application and recommended for use on older DOS-based or Win 95/98 systems. It can be used on modern systems inside of an emulator like DOSBox. The most recent version of FUSION is 3.0, released in 2000 and available from Emulators, Inc.
FUSION can run Mac OS 7.0.1 to 8.1 within its emulated Macintosh.
Fusion was originally developed by Microcode Solutions, an old player in the commercial Macintosh emulation market. Before founding Microcode, company President and CEO Jim Drew spent time with a business called Utilities Unlimited International which created EMPLANT, a means of emulating the Macintosh computer on Amiga machines via hardware purchased from the company. Drew described the EMPLANT hardware as “basically a Mac II motherboard on an Amiga plug-in card.”
Competition from Christian Bauer's ShapeShifter, a shareware Mac-on-Amiga emulator, put UUI out of business in 1995. Drew, however, continued his emulation work by founding “Microcode Solutions” with developer Joe Fenton on August 24 1996. Microcode developed “Fusion,” a software-only (no costly hardware required) Macintosh emulator for the Amiga system. Fusion was ported to x86 (PC) architecture and released as “Fusion-PC” in July of 1998. A demo version of the emulator was released soon afterwards, and the official Microcode site logged over two million downloads of it in less than three years. Though quite popular, initial releases of Fusion-PC ran solely in DOS, causing difficulty for many users. Later releases corrected this problem by giving Fusion the ability to run in a DOS window.
On May 23 2000, Jim Drew sold Fusion-PC to Darek Mihocka's “Emulators, Inc.,” a rival company with a similarly long history in Macintosh emulation on various platforms. Drew stated that he could no longer afford to support an antiquated program while attempting to create an emulator of PPC Macintosh computers.
In April of 2001, Microcode Solutions released “iFusion,” a software-only emulator of the PPC Macintosh for the Amiga computer. The company stated at that time that a port of iFusion to the Windows operating system was almost complete. Drew indicated then that the initial port of iFusion would require hardware support, but that a software-only version would be released at a later date. Drew later sold iFusion for Amiga to a retailer called “Virtual Programming Limited” without releasing a Windows port. Microcode-Solutions has been inactive since about 2002.