Short for Microsoft Disk Operating System. Developed by Microsoft during the 80's with a final release in the 2000. Is a non-graphical command line operating system, meaning you only use a commmand line instead of a graphical interface.
Can be emulated with: DOSBox
First released in 1992, it was a 16-bit series of operating system with a graphical interface over MS-DOS. Can be installed inside DOSBox.
Released in 1995 (hence the name).