As part of a [project to get LaTeX to output something useful](http://tex.blogoverflow.com/2011/07/getting-latex-on-to-the-web/), I found myself wanting to write a new [hyperref](http://www.ctan.org/pkg/hyperref) driver for the desired format. The documentation explains what a driver needs to do, but it doesn't explain how to get hyperref to load the new driver instead of its given one. Looking through the code, I can't see an obvious hook but I may well be missing something. At the moment, I load the driver file using the `\AtBeginDocument` hook, but it worries me that this might not be very robust.

So, can I get hyperref to load a custom driver *without* modifying `hyperref.sty`? If not, are there any dangers from manually loading it myself at the start of the actual document?