<< Hmm, I think you're confusing something here. *NIX systems had (still have in an odd sense) and 8 character limit for usernames, not executables though.
Most *NIX systems allow more than 8 characters for usernames now, it's just that certain programs won't display those properly (i.e. last, it's an issue with wtmp as I recall).
I don't remember there ever being an 8 character limit for executables though. Granted I can only go back about as far as 1985 from my experience, but.... >>
No no, I meant in comparison to DOS. it had the 8.3 format that it had to stick to, so traceroute became tracert.exe