I use FreeDOS for a LiveUSB/CD I make. It includ~1 some basic utiliti~1 such as hard disk testing tools etc. we use at work.
Don't worry, it also includes a FreeBSD part
The main reason I use FreeDOS by the way is because our techni~1 are used to the various tools. But it also comes in handy when flashing mainbo~1, even some fairly recent ones only support flashing the BIOS from DOS.
In general, however, I believe DOS is a piece of junk, and most contem~1 OS's fared better on almost every single point at least since the late 80's...