tor-doc-unix still recommends installing torbutton
https://www.torproject.org/docs/tor-doc-unix.html.en#using tells you to install Torbutton.
More generally, this whole page is telling you the wrong way to do things, now that Tor Browser Bundle Linux exists.
Similarly, https://www.torproject.org/docs/tor-doc-osx tells people to use the Vidalia bundle installer on OS X, and tells people it includes polipo.
At least https://www.torproject.org/docs/tor-doc-windows tells people to use TBB at the top, but I wonder if that's loud enough.