See dunham's answer. Anyone who has seen a PDF file in text form would swear they're looking at Postscript. There's a common intersection that's identical. Ver

See dunham's answer. Anyone who has seen a PDF file in text form would swear they're looking at Postscript. There's a common intersection that's identical. Very roughly speaking (this is a semantic debate where everyone is wrong from someone else's perspective), a PDF file is a restricted subset of Postscript, with added indexes so one can render pages in the middle without having to process the code from the beginning. The hardship in generating PDFs from scratch is getting those indexes right. It's far easier to convert a Postscript file using standard tools.