Cailliau also mentions incorporating into browsers the ability to
> a few wisely chosen formats (for graphics)
including Adobe's new PDF format.
Adobe offers a public specification for PDF in the "Portable Document
Format Reference Manual" (Addison-Wesley, ISBN 0-201-62628-4, US$
24.95). It doesn't seem to be available from Adobe's server,
ftp.adobe.com (188.8.131.52), but it's available from booksellers.
There may be more information available from the Adobe Developers
Association (US$ 195 to join, +1 415-961-4111 or +31-20-6511-200).
Here's what's interesting so far:
PDF files are much more compact than PostScript files.
Adobe offers commercial products that will generate a PDF file from
any Mac or Windows application and from any PS file generated on any
Unlike PS, text can be extracted easily from PDF files for copying.
PDF files can contain hyperlinks -- though only within the PDF file.
It appears the format of PDF link annotations could be extended to
accomodate URLs, if browsers were available to read them.
PDF hyperlinks are rectangles on a page (that is, they are not
anchored in text and can be placed over nontextual matter).
Adobe has stated that the PDF format is extensible and indicated a
willingness to work with third-party developers (unfortunately,
Adobe's organization is such that commercial developers gain easier
I'd be happy to hear from anyone who's interested in working with
Adobe. Perhaps we can develop interest in WWW at Adobe.