FreeDOS

FreeDOS is an open-source DOS-compatible operating system. It supports classic DOS programs, games, and legacy hardware operations. Users can run command-line tools, memory managers, and older software built for MS-DOS. A package manager, FDIMPLES, installs extra utilities. While not a modern OS for daily tasks, FreeDOS is popular for retro computing, embedded systems, or firmware flashing tasks. It’s completely free and community-maintained, preserving DOS environment for hobbyists, system restoration, or specialized applications needing DOS-level access to hardware.