> Now I'm interested to know which languages exist that don't rely heavily on backslashes.

I posit that line continuations don't count, at least not in the "rely heavily" category.

Then I am not sure how popular J and Icon are. So let' keep those away. Is the backlash really used that often in Prolog? I wouldn't say "heavily". So that leaves us with:

    * Perl
    * Haskell
    * Tex

I think that's a more realistic "rely heavily" category.