Alright, let's do ruby then. I use vim with Ri, Rdoc, and ack-grep plugins (https://github.com/kristopolous/vimbuild) and then use irb with a bunch of extensions (http://stackoverflow.com/questions/2952793/anything-like-bpy...) but there is nothing out there that makes my life phenomenally easy yet (for instance, some really awesome code navigation tool). zsh has built-in autocomplete for ri; try running zsh then do "ri <tab>" (http://qaa.ath.cx/ri.png); that ought to win you to at least having it installed. And yes, you can do "ri XXX#<tab>" for the second level! (http://qaa.ath.cx/ri-kernel.png)

For the record, I do straight ruby; I don't even know how to deploy rails.

How are you getting this completion from ri ? I use zsh, and the rvm's ri (.rvm/rubies/ruby-1.9.2-head/bin/ri) gives no completion at all (ri 2.5.8).

However, /usr/bin/ri (ri v1.0.1 - 20041108) does give completion but different from your list. ri K<tab> gives Classes and methods (e.g. Kconv\#guess) and not just classes. So it's a huge list. Thx.