Actually, while developing this I was really struck by the similarities. With the automatic indenting in emacs for lisp (really quite good), it looks very similar, and it's impossible to leave a tag unclosed, but there's a further gain for using parentheses in that with paren-highlighting, you can tell exactly which tag your in. While I converted several dozen pages to this system from straight html, I was saved again and again by this.

HAML's great, and I disagree with the other "I hate haml" post on the frontpage today, but this approach actually alleviates the issues pointed out with haml's whitespace-is-meaningful approach.

Anyway, it's all in good fun.