Command-line-wise, almost none, although this has
been changing (for better or worse). Linux has a much larger market
appeal and following than any commercial UNIX. GUI-wise there are
also no major differences--Linux, as most other UNIXes, uses an
The major differences:
Linux is free, while many UNICES (this is
supposed to be the plural of UNIX), are very expensive. The same
for applications--many good applications are available on Linux
free. Even the same commercial application (if you wanted to buy
one) typically costs much more for a commercial UNIX than for Linux.
Linux runs on many hardware platforms, the
commodity Intel-x86/IBM-spec personal computers being the most
prominent. In contrast, a typical UNIX is
proprietary-hardware-bonded (and this hardware tends to be much more
expensive than a typical PC clone).
With Linux, you are in charge of your
computer, whereas on most UNICES you are typically confined to be an
"l-user" (some administrators pronounce it "loser").
Linux feels very much like DOS/Win in the
late 80s/90s, but is much sturdier and richer, while a typical UNIX
account feels like a mainframe from the 60s/70s.
Some UNICES may be more mature in certain
areas (for example, security, some engineering applications, better
support of cutting-edge hardware). Linux is more for the average Joe
who wants to run his own server or engineering workstation.