My friend Martin sent me this through email: A paper by Bjarne Stroustroup on overloading the whitespace operator in C++. It would allow expressions such as z = x y instead of z = x * y and other interesting and (incredibly useful!) applications. Most interesting of all is the impact of this new operator on non-ASCII character sets, and the final recommendations they make for implementing it, near the end, so that it can be useful in 3D display devices. A must read.

Chris then sent another, more current (from this year) effort in this direction: the Whitespace programming language:

Most modern programming languages do not consider white space characters (spaces, tabs and newlines) syntax, ignoring them, as if they weren't there. Whitespace is a language that seeks to redress the balance. Any non whitespace characters are ignored; only spaces, tabs and newlines are considered syntax.