FreeDOS is an open-source operating system that is compatible with MS-DOS. It allows users to run legacy software and games that were designed for DOS environments. FreeDOS is particularly useful for those who want to maintain older systems or run specific applications that require a DOS interface. The project was initiated in 1994 and has since grown with contributions from a community of developers. FreeDOS is freely available for download and can be installed on various hardware platforms, making it a versatile choice for users looking to experience or utilize DOS-based applications without the need for proprietary software.