[Coco] Re: why you should stick with pdf

[John E. Malmberg]

Gene Heskett wrote:
> 
> If pushed to the wall, I'd expect pdf to pretty well match the 
> commercial djvu in terms of output size.  At that point, one should 
> compare the cpu cycles used to do the compression.
> And of course theres the fact that pdf has been around what, 20 years 
> now that I'm aware of, so its mature, but young enough to be around 
> for another 50 or so before its really considered to be excessively 
> long in the tooth.

There are several revisions of the PDF format, and some of the latest 
are only a year old.  The open source viewers are usually at least a 
couple of revisions behind.

In the last two years, I have had to update the Adobe PDF viewers on my 
Windows systems several times to keep up with the changes.

So while PDF 1.0 is mature, in use PDF is very young.

The PDF specification is quite complex, and I occasionally encounter PDF 
documents that XPDF only displays as blank or XPDF just does a core dump 
when it runs.

I do not know that the specification published by Adobe to the public is 
current and with out errors.

PDF is only fully portable for platforms that Adobe has released 
supported viewers for.

Anything else is only supporting an *UNKNOWN* subset of the PDF that is 
possibly more out of date with each new change that Adobe may insert 
with out notice.

So if you generate the PDF document with an open source tool, then it is 
likely that it can be viewed everywhere.  But at the same time, it will 
not be using the latest or even all of the features of PDF.

If you generate PDF from an Adobe licensed tool, then it is possible 
that the output will be viewable on open source readers, but it is also 
possible that the output will only be able to be viewed on PDF readers 
supplied by Adobe.

Until Adobe releases reference source code for a current Adobe file 
rendering system for UNIX/LINUX it will remain that way.

It also appears that Adobe is no longer offering a Java viewer. 
Supported Viewers are available for Windows, Apple, various other 
platforms, including X86 LINUX, HP-UX and such.

But not all LINUXes platforms are supported.

With the DjVU format, there are binaries for the major platforms just 
like there are for PDF.  In that they are equal.

The difference is that with DjVU, the source for the viewer can also be 
put on the DVD so that what ever platform you have in the future can 
build the reader if it can not use the existing binary.

Adobe has also dropped support for platforms from it's reader in the 
past.  X86 LINUX/Windows and Macintosh OSes probably do not have much to 
be concerned about.  Other platforms may need to be concerned.

-John
wb8tyw(at)qsl.network
Personal Opinion Only