When I'm creating graphics in Photoshop or Illustrator, I often wish my work was entirely represented by some plain-text format so that I could dive down and make rapid changes without doing too much work. (For example: changing the properties of a bunch of text labels at once, or instancing a similar object several times, or globally changing a color that applies to multiple objects.) I suppose it would sort of work like a WYSIWYG web development application, where you would do most of your work with the UI toolset but dive down into the raw HTML/CSS on occasion. Postscript seems like a good candidate, but I don't think I've seen anything that uses it in such a way. Are there any tools like this already available?
(PaintCode looks similar to what I'm describing, but I don't think it's as robust as Illustrator for example.)