Think of it as Unix Lite.Nope. First I thought you meant DOS, but I googled it and I was wrong, lol. How was it like?
It's portable, running under DOS, DEC VAX, Apple 2e, & others.
I used to use it in native mode until PCs got fast. Running under DOS slows it down a lot.
It's multi-tasking, with no memory conflicts & little memory required.
It's menu driven & text based.
It's absolutely bullet proof, which is why I've been running business software under it for almost 30 years.
It's poorly documented, & the support is even worse.
It's rare in the US.