If you have an old collection of PC MS-DOS games that has been sleeping at the bottom of a drawer, you may have two approaches: A/ you prefer to forget the old pixels and buy new games, B/ you were so found of those that you want to play even on your newest PC. However, it is difficult because most of these run only in a DOS box, but are so unusable because of the speed of the processor and the limited compatibility of the sound and graphics.
Now DOSBox.com offers a real solution with a free emulator.
Usable for MS-Windows, most Linux boxes, some Apple OS and OS/2.