This has just become my favorite programming language of all time: http://compsoc.dur.ac.uk/whitespace/.
Most modern programming languages do not consider white space characters (spaces, tabs and newlines) syntax, ignoring them, as if they weren't there.... Whitespace seeks to redress the balance. Any non whitespace characters are ignored; only spaces, tabs and newlines are considered syntax.
Just don't expect me to attempt to write any programs in it. Ever.