The Multics CPU simulator
The Multics CPU simulator created by Harry Reed and Charles Anthony is available for public download. A complete QuickStart installation package is available that provides software, compilers, system source, install scripts, and several initial projects (SysDaemon, SysAdmin, Daemon, etc.) and users.This is Multics, the complete multi-user operating system, running on a simulated Honeywell DPS8M processor. The simulator is available for Mac OS X, Linux, or Windows, both 32bit and 64bit versions, and also supports the Raspberry Pi.