Package SheepShaver: Information

SheepShaver is a MacOS run-time environment for BeOS and Linux that
allows you to run classic MacOS applications inside the BeOS/Linux
multitasking environment. This means that both BeOS/Linux and MacOS
applications can run at the same time (usually in a window on the
BeOS/Linux desktop) and data can be exchanged between them. If you are
using a PowerPC-based system, applications will run at native speed
(i.e. with no emulation involved). There is also a built-in PowerPC
emulator for non-PowerPC systems.

SheepShaver is distributed under the terms of the GNU General Public
License (GPL). However, you still need a copy of MacOS and a PowerMac
ROM image to use SheepShaver. If you're planning to run SheepShaver on
a PowerMac, you probably already have these two items.