If you're of a certain age you will probably have used Windows 3.1 on a PC. Windows 3 and its descendants was the first mass market GUI operating system for the PC. For those who couldn't afford a Macintosh this was regular folks' release from the tyranny of the command prompt. Many of its features and some of its look and feel are still visible in modern incarnations of Windows. Some clever people at the Internet Archive have created a version of the Windows 3.1 OS that will run in your web browser along with 1,500 Windows 3.1 shareware apps, including classic games like WinRisk.
from The Universal Machine http://universal-machine.blogspot.com/