weird, my Alfa Romeo user manual is 270 pages filled with graphics (literally, they are jpeg scanned to a pdf) and loads instantly even on my mobile phone
The first page is rendered instantly you mean. PDF, at least when generated by a sane generator, can be parsed pagewise. HTML cannot, you always have to parse everything in a page to do layout, because later objects can change or overlay earlier ones.
> HTML cannot, you always have to parse everything in a page to do layout, because later objects can change or overlay earlier ones.
HTML is progressively rendered by default. This has been a feature since Netscape 1.0! It is only if you use certain types of layout this is not possible. For example an adaptive table have to be fully loaded before the width of the columns can be calculated.
Is PDF still unstreamable? AFAIK, the TOC (catalog?) in a PDF was located at the end of the file, meaning the whole PDF had to come down in order to parse the PDF. (With the exception of the first page, as you say — some aspect of the PDF spec allowed for a self-contained page 1.)
