If you're planning on running the treasures of the past you'll find here on real old Macintosh hardware from the 90's, you sir/madame, deserve to win an Internet! For others, there's SheepShaver, a PowerPC emulator capable of running Mac OS 9.0.4 down to Mac OS 7.5.2 and there's Basilisk II, a 68k emulator , capable of running Mac OS (8.1 to 7.0). For everything older than System 7, you will need a Mac Plus emulator like Mini vMac Since August 2016, it is now possible to emulate a PPC and boot Mac OS 9.2.2 using QEMU Quick tip about Basilisk II if you do not have a real old Mac: it even reads high density Mac floppy disks using a normal PC floppy drive! I salvaged many old files using it while 5 different Windows apps failed at the task. I highly recommend backing up all your floppy disks using Basilisk II before it's too late!