It can be educating to look at the history of Reia (Python/Ruby-like language for Erlang VM). At first its author tried to hard to make Reia indentation sensitive (like Python). Finally he reconsidered after discovering several limitiations: <a href="http://www.unlimitednovelty.com/2009/03/indentation-sensitivity-post-mortem.html" rel="nofollow">http://www.unlimitednovelty.com/2009/03/indentation-sensitiv...</a>