SheepShaver is an Open Source PowerPC Mac OS run-time environment. That is, it enables you to run PowerPC Classic Mac OS software on your computer, even if you are using a different operating system. However, you still need a copy of Mac OS and a PowerMac ROM image to use this program. SheepShaver is distributed under the terms of the GNU General Public License (GPL).
If you are using a PowerPC-based system, applications will run at native speeds (i.e., without any emulation involved). On other systems, SheepShaver provides the first PowerPC G4 emulator, though without MMU, to enable the execution of Mac OS Classic. Performance with the current CPU emulator using basic just-in-time (JIT) translation techniques is roughly 1/8-th of native speeds.
The following platforms are currently supported: Linux (i386, ppc, x86_64), MacOS X (i386, ppc), Darwin, NetBSD 2.0, FreeBSD 5.3 and Windows for x86. Please note that I am pretty careless of the Windows version since I am not a Windows developer. You are heartily invited to join the effort!
Updated on Apr 06 2021