I translated into Arc a little program I wrote a few months ago to compare the distribution of characters in Qwerty vs. Dvorak by hands, fingers, etc. It currently outputs text; the next step of course is to output HTML.
Getting the program to work was a bitch as there doesn't seem to be any debugging support at all. Nevertheless, I'm extremely pleased with the language itself.
The utility at the beginning reflects the only serious issue I ran into: objs don't seem to be able refer to themselves. I had to write a new obj macro that binds the current object to 'this'.
Also, although it's not a serious problem, I'd love to be able to refer to obj fields with a simpler syntax, e.g. x.foo instead of (x 'foo). In particular, that quote before the field name is kind of a wart.