Don't know about Quark but InDesign allows you to create an RGB / pixel based documents (like Illustrator). Suppose Quark works the same way. It's all HTML5. Here is a tutorial I just found http://www.jamie-cross.net/?cat=26
From a developer's perceptive it might suck, but from a designer's perceptive it's 'good enough' and better than static PDF files like InDesign creates.