PDF is cross platform, operating system independent, vendor independent and most importantly, completely portable. I believe this is why PDF has become the defacto standard because it can be sent anywhere, to any device on any platform.
The biggest restriction for portability with PDF is the availability and the richness of the toolset on each platform. Adobe, since version 4, have concentrated solely on Macintosh and Windows and with the release of version 6 Adobe have put what appears to be considerably more resources behind the Windows release of Acrobat than the apparently equivalent version on the Macintosh.
When we look at the portability of FlashPaper we need to think about the available viewing technologies. FlashPaper requires a Flash Viewer (ShockWave, Director etc) to be present which limits the choice of platforms and operating systems considerably, it also requires that the Flash Viewer can read version 6 and above ShockWave documents (SWF).
Adobe Reader and Macromedia Flash Player are available for a number of platforms and languages. The Adobe Reader and Macromedia Flash Player download pages include the complete lists. The full list of languages supported by Flash Player is available from that product's FAQ.
FlashPaper is over a year old now (since 2003) and although that's not a significant enough history for a version 1.x product to see how future-proof it is, we can gather enough data to make some assumptions about what features will be available in future versions of Flash and which features will be dropped or replaced with new technologies/features.
In my opinion FlashPaper, like PDF will continue to be backward compatible, meaning a document created in FlashPaper version 1.0 will be readable by Flash viewers many years to come, however due to the more dynamic nature of the FlashPaper viewer I believe a dynamic upgrade/conversion will happen to older FlashPaper documents automatically - what the consequences of that will be remain to be seen (or even if this process even happens).
A major drawback for FlashPaper is that only version 6 Flash Players and above can view and make use of FlashPaper documents.
PDF has proved itself to be stable and strongly backward compatible. This isn't to say that the PDF specification has changed and not broken past features, rather this has only happened on few occasions.
For the cases I can think off, the change/break in backward compatibility has only been in the spec - Acrobat (full version) has always been able to deal with older PDF files and generally prompted for the repair/upgrade of the older PDF files.
Fonts and Graphics
Two of the biggest strengths of PDF are its ability to embed fonts and its ability to include almost any type of graphics. These two features get around a lot of the problems encountered by proprietary formats.
When a PDF is created the author of the PDF can rest assured that the text in the PDF will look exactly as it did in the original source document - this is because the actual fonts used in the source program can be included (or only the characters in the font set that were used by the source documents) in the PDF.
Text in Adobe Reader, Zoomed in to 6400% Magnification. The sharpness is still clearly visible.
This really does provide WYSIWYG (What You See Is What You Get) documents. It also means that authors of PDF files on Unix or Macintosh no longer have to struggle with fonts issues when distributing their files to Windows users. The big gotcha of course is Font Licensing - Acrobat cannot embed/subset (include) a font that has licensing restrictions - which means the author of the PDF has to think about how and where the PDF will be distributed for the consideration of fonts.
If the user receives the PDF and the own and have installed the font on their machine then Acrobat/PDF can easily display the text in the way it was intended - but what happens if they don't have the font? Well it turns out that Acrobat can do a substitution on the font, providing its best guess look-alike for the originally used font.
When a PDF is created any graphics in the source document are automatically converted and included in the PDF - via Acrobat Distiller the author of the PDF also has complete control over the compression of the graphics: everything from specifying the type of compression used for different types of graphics to being able to reduce the resolution of the graphics for the reduction of the resultant file.
During the process of creating a FlashPaper document the fonts are rasterised, this prevents many of the features we have grown use to from actually being available -- such as text selection and font embedding.
FlashPaper Viewer: Maximum Zoom is 250%. Note control over compression of Graphics is provided.
To create a FlashPaper document the FlashPaper Printer Driver is actually requesting the graphics context information from the operating system, essentially 'screen scraping' the source document into a FlashPaper document.
This is akin to Adobe's PDFWriter technology that leveraged the Microsoft Windows GDI (or Mac QuickTime) to generate PDF's. The quality is always lower due to the limitations of rasterised graphics and the operating systems ability to generate high quality screens and the features found in the resultant PDF were significantly less (i.e., no font selection, font embedding, vector graphics etc).
Adobe no longer distributes the PDFWriter technology (as of version 6), instead opting to generate PDF documents via Postscript/Distillation techniques. The quality that is gained (not to mention the retention of vector artwork and font embedding) through the Postscript -> PDF process is far greater than the process gained through the generation of PDF's via operating system based graphics content.
OK, so you want to stamp your document. Maybe you need to give reviewers some advice about the document's status or sensitivity. This tip from author Ted Padova demonstrates how to add stamps with the Stamp Tool along with related comments.