Last time I checked, the only thing I could find separating Linux from 
UNIX was the free availability of a compression algorithm and some fees. 
I'm not 100% sure of that, but that was my interpretation at the time.  I 
believe the compression algorithm patent has expired and the 
UNIX-compatible compress program is available with Linux now.

So, GNU's Not UNIX, but is Linux UNIX?  Why or why not?

Mike