I need to write a "virtual printer driver" for OSX, so that when the user presses Command+P to open the Print dialog, he sees my virtual printer...which will be used to generate files of various types, instead of physically printing to paper.
I'm new to the subject, I looked around a bit but found nothing. Do you have any link or reference to documentation that cover this topic?
Rather than writing a driver, consider using the PDF Services feature of OS X print dialogs. In either the system-wide /Library/PDF Services or a user's ~/Library/PDF Services directory, you can put AppleScripts, Automator workflows, or symlinks/aliases to applications or folders. Those items will appear in the PDF pop-up menu in the print dialog, and if the user selects the item, a PDF of the file will be placed in the folder or be passed to the application, script, or workflow.