All the open-standards advocates lobbying for PDF to be brought into the public domain can breathe easier now. It's done, ratified officially as "ISO 32000—Document management—Portable document format—PDF 1.7."

While Adobe had decided to submit PDF to ISO just last year, making PDF an open standard was much longer in the making.

"Ever since 1993, it would come up. People would ask 'Why don't you make it a public standard?' and we'd say 'No,'" says James King, Adobe PDF Architect and a Senior Principal Scientist serving as the PDF standard's technical editor for the ISO working group. King was charged with hashing out the technical issues raised in some 205 comments filed between last July and December after Adobe submitted the PDF spec to ISO via its U.S. members ANSI and AIIM.

But increasing pressure from European governments, coupled with a controversy three years ago over the Massachusetts state government's ODF stance, changed things. The latter left Microsoft fuming and gave a much stronger voice to open-standards advocates. King says these independent forces made Adobe realize that it finally made sense to formally give PDF over to ISO.

"Eventually, we just decided the time was right; it was a mature enough technology."

Adobe had worked hard to be what King calls "good shepherds" of the PDF standard, in order to keep public versions readable and something upon which third parties could develop their own software and applications. The standard's maturity and widespread adoption made fast tracking—an ISO process designed to speed ratification of already established standards—possible for the 1.7 edition of PDF.

King says he and longtime PDF veteran (currently an Adobe technical evangelist) Leonard Rosenthol spent a long time going through the spec and "cleaning it up." They deleted references to Adobe (who no longer owns the spec), Acrobat, and Reader, and replaced those terms with words like "developers," "software," and document "readers." The two also streamlined verbiage that had become tangled through the years as the PDF spec was upgraded and rewritten; in addition, they made sure that the spec reflects what each of the billions of PDF files in use today actually contains, and wherever possible, they adapted the spec to ISO's style of standards documentation.

Still, underscoring how dense the PDF spec is, many of the 205 comments that King and Rosenthol had to address between conditional ratification in December and the final vote last week included typos or confusing verbiage, although some experts had other specific technical changes or additions. King was able to resolve the suggested changes to the ISO committee's satisfaction, to the point where the French expert dropped his lone dissenting vote and made approval unanimous.

Work on the next PDF spec, ISO 32000-2, has already begun, King says, with discussions underway on about 15 additions. He says he hopes that ISO will retain two major principles Adobe stuck with in developing the PDF standard over the years: never obsoleting a file, meaning that 1.0 PDFs will open in current versions of Reader, and making new PDFs openable in previous versions of Acrobat and Reader. (As you go further back, things like video or Flash aren't viewable, but at least the documents open and the text is there.) But that's not for Adobe to decide anymore, because the company's not in charge of PDF anymore—though it still has a voice at the table.

"Those were two principles we followed, with tough arguments and long discussions," says King, whose 20-year tenure at Adobe predates Acrobat and PDF. "I want to try to impress on the standards group they should continue to follow them."