Adobe Systems announced that it has developed a PostScript-based technol- ogy for exchanging formatted elec- tronic documents. Adobe's approach to this problem draws on several existing technologies, including the Illustrator file format, Multiple Master fonts and a newly announced font rasterizing chip. However, Adobe is not announcing any specific product at this time.
When Adobe's vision is fully fleshed out with deliverable products, it promises to let you move documents freely around a network, viewing them on a wide range of computer platforms. Although these documents will be in final form and ready for presentation, they will continue to be editable.
As John Warnock was expected to sketch out in a speech to the Seybold Computer Publishing Conference this week, much of the software needed to do this already exists. The remaining problems are partly legal and licensing issues, and partly a continuing process of developing standards.
Illustrator 3.0 does not handle all document types, of course. It knows nothing of multipage documents, style sheets, reference constructs or scanned images. In IPF (and presumably in fu- ture Illustrator-like products), Adobe clearly intends to extend the range of objects to cope with these needs.
This is relatively straightforward; PostScript was from the beginning de- signed to be device independent. At the Seybold Conference, Warnock was expected to demonstrate the new tech- nology on a Mac, PCs running DOS and Windows, and a Unix workstation.
Adobe's solution here is two- pronged. First, Adobe says, all you need to send is the font metrics--the character widths and kerning tables. At the receiving end, a document viewer program can use Multiple Master fonts to generate good-looking type that ex- actly matches the formatting of the original text. In fact, Adobe claims that for most normal text faces, the on- screen appearance of the synthesized fonts will be indistinguishable from the original fonts.
However, there is a fall-back approach: send the fonts. Adobe is work- ing with other major font vendors to modify the shrink-wrap font license to permit distribution for read-only or print-only use. Adobe will license this use for its own fonts, and the ITC (the licensing agency for a substantial fraction of everybody's font libraries) has agreed to do so as well. The other font houses will probably go along sooner or later.
(A third method--sending along the name of the font and its metrics- depends on a standardized naming scheme and presumes font-substitution smarts by a viewer at the other end. This method is being considered for ISO interchange formats.)
Adobe announced last winter that it would be developing the PostScript drivers for future Apple and Windows operating systems. So it will simply add to its drivers the ability to generate an IPF file. At that point, every existing application will be able to create inter- change-ready documents.
There is an installed base of older applications that generate their own PostScript code and so will not benefit from Adobe's new device drivers. A program that converts the full range of PostScript into the more restrictive IPF would be tantamount to a complete PostScript interpreter. This is exactly how Adobe plans to assure backward compatibility.
However, Adobe points out that you wouldn't need this interpreter in every workstation. You could run it as a task at one station on the network-- in the mail server, for example.
Adobe has not given any hints about when such viewers might be released. However, the core code has already been written and demonstrated, so we don't expect to wait years. We might hope for an announcement next spring; but Adobe has politely declined to speculate on that subject.
Adobe says that text rendering is so fast with its new "ATM chip" that you can continuously zoom a page with no perceptible jerkiness--new full- page bitmaps can be generated at speeds comparable with the monitor's frame rate. This kind of hardware accel- eration will clearly be vital in gaining consumer acceptance of PostScript for viewing documents.
Adobe's format will be implemented immediately by Adobe, and its status as a "standard" could change if it meets with popular acceptance. (After all, PostScript has become an ISO standard.) Everything depends on how well Adobe's implementations meet users' requirements for electronic document interchange.
Seybold Report on Desktop Publishing; October 2, 1991