[tryauuum]

This made me question my belief that DOS is an operating system. If it cannot run programs with (fake) parallelism and doesn't have virtual memory...

[zaat]

Well, if it isn't operating system, than what is it exactly?

[hdjjhhvvhga]

A good base to develop an RTOS[0] for example with RTKernel[1] on some hardware.

[0] https://en.wikibooks.org/wiki/Embedded_Systems/Common_RTOS/D...

[1] http://www.on-time.com/rtkernel-dos.htm

[giantrobot]

A runtime library.