The Internet Archive has an emulator for playing Nuclear War, an MS-DOS game from 1989.
The classic Ancient Art of War game, released by Broderbund in 1984, is available to play on archive.org in an emulator.
Gary Grigsby’s Pacific War was a lot of fun in the days of MS-DOS gaming. You can play it again on the Web Archive MS-DOS simulator.
Card Creator is a piece of software that helps you design your own Magic-style cards.