System 9.x
and before are
 "something different" for me, a break from my mostly hardcore CLI
 existence. 
 Yes, true. An OS I still miss, for all its instability and quirkiness.
 I'd love to see a modern FOSS recreation, at least of the concept and
 the style, even if it was binary-incompatible. 
 
   What do you feel is still missing from OS-X today?  About the only thing I
 can think of is the unique file system, where each file had a data and a
 resource fork.