PDF is an "ad hoc" standard right now.  It is on the path to being an 
official standard (ISO 32000) but it's not there yet.  Honestly, saying 
it's not a standard because it doesn't have an ISO code attached to it 
is nit-picking to an extreme.

Adobe has always released the specifications of PDF and anybody is free 
to implement it.  Yes, Adobe does charge for their Acrobat Professional 
suite, but it's hardly required.  There are scads of PDF-capable apps 
out there.  Heck, OS X works with PDF as a native subsystem.  In no 
cases do you have to pay any sort of royalty or sign any agreement with 
Adobe to implement it.

To sum:
1. Specification widely available... Check
2. Anybody can implement the spec royalty and patent free (now that the 
LZW patent has expired)... Check
3. Documents in PDF format are pervasively and inescapably common... Check
4. A multitude of 3rd party reader and writers for PDF... Check

If that's not a standard, then we have very different ideas on what a 
standard is. :-)

eculbert wrote:
> No more than windows is a 'standard' I believe. It IS
> wide spread, but with the exception of the windoze
> reader, adobe charges, but the ability to implement
> apparently is NOT infringement or all the major
> distro's would be being sued by Adobe. So IF that is
> what makes it a standard, then so be it.
> 
> My quarter cent worth.
> 
> Ed
> 
> --- Chris Gehlker <canyonrat@mac.com> wrote:
> 
>> On May 24, 2008, at 2:36 PM, der.hans wrote:
>>
>>> Is PDF a standard? I thought PDF was owned and run
>> by Adobe, but  
>>> they were
>>> allowing 3rd party implementation.
>> Wikipedia says it's a standard:
>>
> <http://en.wikipedia.org/wiki/Portable_Document_Format>