Unix Rosetta Stone

I just found the Unix Rosetta Stone which seems simplified, but still probably handy if you've got a really heterogeneous network, or if an AIX machine should suddenly spring up in the middle of the server room.

Judging from the number of Delicious bookmarks it has, it's pretty well know, but I figured that I couldn't be the only person in the dark, and I figured someone might get some info from it.