Brings back memories of playing around in the shell on an Atari TT at CeBit '91 or so. Having had an apprenticeship in a company producing their own machines (Norsk Data) and porting System V, as well as having used Atari GEM graphic shells, made me want to avoid DOS or even CP/M for personal use and especially development at the time ;) Then used AIX and Interactive Systems professionally until Linux and the BSDs came about. There was also a short period in 1992 or so when I had the option to use A/UX (Apple's System V port at the time) as file server, though NetWare 2 and 3 were cheaper and better suited for DOS/Windows networking.