FreeDOS is a free, open-source operating system compatible with MS-DOS. It's designed to run legacy DOS programs, including classic games and business software. This latest release features an updated FreeCOM, enhanced help, and improvements to utilities such as FDISK, 7-Zip, and FASM.
Facepalm: Microsoft deserves kudos for open-sourcing the MS-DOS 4.00 source code, shedding light on an important milestone in computing history. But the tech giant has bungled the release in a way that may cause needless headaches for historians and archivists eager to study the decades-old code.