[O] Use custom program to process LaTeX fragments?

Currently, whenever you export to HTML, you have 3 options for processing LaTeX fragments: (1) dvipng, (2) jsmath, (3) or leave it as is. Is it possible to use an arbitrary program to process LaTeX fragments? What I want to do is use a commandline converter to turn the LaTeX fragments directl

[O] Stop inserting default CSS in HTML export?

How can I get org-mode to stop inserting the default CSS in the HTML export? By default, exporting to HTML gives me this CSS defined in the header. I'd like to...well, *not* have it included in the HTML.