From A List Apart. The simple elgance and ergonomics of CSS is something I find fascinating:
A printed book has many features not seen on screens. There are page numbers, headers and footers, a table of contents, and an index. The content must be split into pages of fixed size, and cross-references within the book (for example, â€œsee definition on page 35â€) must be resolved. Finally, the content must be converted to PDF, which is sent to the printer.
Web browsers are good at dealing with pixels on a screen, but not very good at printing. To print a full book we turned to Prince, a dedicated batch processor which converts XML to PDF by way of CSS. Prince supports the print-specific features of CSS2, as well as functionality proposed for CSS3.