How do you run Classic on Mac OS X?

The Classic environment allowed Macintosh software from the pre Mac OS X era to run on Macs using Mac OS X. Classic is not available on Macs with Intel processors or running Mac OS X 10.5 (Leopard).

To run Classic you need an older PPC Mac (G5 or G4) and Mac OS X 10.4 (Tiger) with Mac OS 9 installed. Double clicking an old application will launch the Classic environment and run the software.