[bch]

To my point of no keywords, and touching on the interesting model @groovy2shoes is talking about here[1]:

  $ tclsh

  % set a set
  set
  % puts $a
  set
  % $a b 9
  9
  % set b
  9
  % set set set
  set
  % $set set
  set
  % rename set foo
  % foo set
  set
  % foo a
  set
  % foo a 9
  9
  % puts $a
  9
  %

[1] http://news.ycombinator.com/item?id=3536419

[edit: formatting]