I agree with tptacek that this is a red herring, but I disagree about why. Maybe I've been lucky, but all the designers I've interacted with are plenty good eno

I agree with tptacek that this is a red herring, but I disagree about why. Maybe I've been lucky, but all the designers I've interacted with are plenty good enough to get Haml and (especially) Sass. And most of these designers have liked them. The semantics of Haml and Sass are identical to those of HTML and CSS. The extensions they add are generally clear to anyone familiar with the base languages. And Haml has the great benefit of making HTML be written like CSS, which is much more comfortable to designers.