3 ms·

It's been 30 years. Shouldn't PDF become open source given its popularity?

19 points by behnamoh 3y ago

jjgreen 3y ago
I'll be sticking with Postscript until this PDF newcomer gains some traction ...
- contingencies 3y ago
  PS. Not joking.
PaulHoule 3y ago
PDF has been an ISO standard for a long time (Adobe never would have gotten as much buy in for PDF if it wasn't.) Normally you have to pay 133 CHF for an ISO standard document (... like the technical report I wrote that disappeared somewhere between the committee and the editors ...) but you can download the spec for free here https://opensource.adobe.com/dc-acrobat-sdk-docs/pdfstandards/PDF32000_2008.pdf https://opensource.adobe.com/dc-acrobat-sdk-docs/pdfstandard... There are all kinds of open source implementations https://opensource.com/alternatives/adobe-acrobat https://opensource.com/alternatives/adobe-acrobat
hollasch 3y ago
The PDF format is an open standard, maintained by the International Organization for Standardization (ISO).
solardev 3y ago
The basic format is an open standard (ISO 32000), and many editors & viewers implement the basic functionality. However, PDF also has a bunch of different versions and substandards, and different editors and viewers will support different features: forms, accessibility, encryption, Javascript, layers, embedded Adobe Illustrator data, etc. https://en.wikipedia.org/wiki/PDF#Additional_features https://en.wikipedia.org/wiki/PDF#Additional_features Acrobat probably supports the most features out-of-the-box, and only Illustrator can open Illustrator-in-PDFs, I think. For example, many government forms won't work right in third-party viewers. Like this worker's comp form: https://www.dol.gov/sites/dolgov/files/owcp/regs/compliance/ca-1.pdf https://www.dol.gov/sites/dolgov/files/owcp/regs/compliance/... will have working fields in the Chrome viewer or macOS Preview, but the Print/Save/Reset form buttons at the bottom do nothing unless you open it in Acrobat. Or GeoPDFs, a third-party extension (https://terragotech.com/resources/sample-geopdfs/ https://terragotech.com/resources/sample-geopdfs/) that don't work right at all outside of Acrobat, even though they're used by the USGS (https://www.usgs.gov/faqs/what-geopdfr https://www.usgs.gov/faqs/what-geopdfr). It's kinda like the Word doc situation of the 2000s... third-party utilities can usually open them and get the basic document and formatting, but not perfectly, and some features just won't work.
- eternityforest 3y ago
  Why is the government using non standard features? Did they make it back when people actually used Acrobat?
  - deleted 3y ago
    [deleted]
  - solardev 3y ago
    Hey, give them some credit... at least they upgraded from fax machines a few years ago... ;) ------- Edit: Less snarkily, I think there just aren't a lot of bleeding-edge tech people in civil service, at least in the US. Would you want to give up your cushy dev job to work for a huge bureaucracy at maybe 40% of the industry pay? So you're left with bureaucrats/administrative workers who grew up on MS Office and Adobe Acrobat, and who can't easily switch to new tools even if they wanted to without a horribly complicated purchasing process. Some other countries and small localities experimented with replacing MS Office with OpenOffice, for example, or Windows with Linux but I think most of those failed. Similarly, most government geographical services use ESRI software even though open-source ones have been around for a while. Sometimes it's a matter of feature parity, but more likely than not, only big entities like that are equipped to deal with government contracting and support. Government moves really, really slow, and prefers to work with other huge companies under really complex contracts... it's antithetical to most software/web work. Nobody is going to jump through all those hoops just to get us a slightly more standard PDF form. If you push them too hard they'll probably just go back to paper forms and fax, lol.
j4hdufd8 3y ago
Surely someone has reverse engineered it and open sourced it?
rstuart4133 3y ago
It misses at least one editing tool, which happens to be the one I prefer: xournal. https://xournalpp.github.io/guide/pdfs/ https://xournalpp.github.io/guide/pdfs/ LibreOffice's apps and Inkscape also do the job as they say, but they re-render the existing content which often changes it's look. In particular of it don't have a close matching font installed the result can be a mess. xournal doesn't have that problem but it only lets you add, not delete or modify. No mention of digital (x509) signing. LibreOffice can do it - but see above. Okula can do it reasonably well, if you are prepared to pollute your Firefox certs with your personal ones. I haven't found a command line tool (like pdftk) that does it, which is sad.
- gettalong 3y ago
  If you need a state of the art CLI tool for signing PDFs that supports the latest standards (think ones from 2023), I can recommend pyHanko (https://github.com/MatthiasValvekens/pyHanko/ https://github.com/MatthiasValvekens/pyHanko/).
  - rstuart4133 3y ago
    Thank you. Responses like these make HN awesome.
egberts1 3y ago
Thr short answer is no. Embedding JavaScript is security mistake #1. Placing references at the end of the file is data-extensibility mistake #2. Auto-executing embedded URL is security mistake #3 Disclaimer: I write high-speed PDF parsers for various IDS/XNS/IPS companies.
gettalong 3y ago
It seems that the news hasn't spread far yet but due to sponsorships by various big PDF related companies the ISO standard for PDF 2.0 is freely available, see https://www.pdfa-inc.org/product/iso-32000-2-pdf-2-0-bundle-sponsored-access/ https://www.pdfa-inc.org/product/iso-32000-2-pdf-2-0-bundle-... While the PDF 1.7 spec from Adobe was always available, once it was turned into an ISO spec (ISO 32000-1:2008) it became paywalled. Due to an agreement with Adobe, the ISO version of the PDF 1.7 spec was made available free of charge. However, the further development of the PDF standard was done according to ISO rules and that meant paying for the standard... until the PDF association and a few companies stepped up and made the spec free again (also see https://www.pdfa.org/sponsored-standards/ https://www.pdfa.org/sponsored-standards/).

19 points by behnamoh 3y ago

jjgreen 3y ago

I'll be sticking with Postscript until this PDF newcomer gains some traction ...

contingencies 3y ago
PS. Not joking.

PaulHoule 3y ago

PDF has been an ISO standard for a long time (Adobe never would have gotten as much buy in for PDF if it wasn't.) Normally you have to pay 133 CHF for an ISO standard document (... like the technical report I wrote that disappeared somewhere between the committee and the editors ...) but you can download the spec for free here https://opensource.adobe.com/dc-acrobat-sdk-docs/pdfstandards/PDF32000_2008.pdf https://opensource.adobe.com/dc-acrobat-sdk-docs/pdfstandard... There are all kinds of open source implementations https://opensource.com/alternatives/adobe-acrobat https://opensource.com/alternatives/adobe-acrobat

hollasch 3y ago

The PDF format is an open standard, maintained by the International Organization for Standardization (ISO).

solardev 3y ago

The basic format is an open standard (ISO 32000), and many editors & viewers implement the basic functionality. However, PDF also has a bunch of different versions and substandards, and different editors and viewers will support different features: forms, accessibility, encryption, Javascript, layers, embedded Adobe Illustrator data, etc. https://en.wikipedia.org/wiki/PDF#Additional_features https://en.wikipedia.org/wiki/PDF#Additional_features Acrobat probably supports the most features out-of-the-box, and only Illustrator can open Illustrator-in-PDFs, I think. For example, many government forms won't work right in third-party viewers. Like this worker's comp form: https://www.dol.gov/sites/dolgov/files/owcp/regs/compliance/ca-1.pdf https://www.dol.gov/sites/dolgov/files/owcp/regs/compliance/... will have working fields in the Chrome viewer or macOS Preview, but the Print/Save/Reset form buttons at the bottom do nothing unless you open it in Acrobat. Or GeoPDFs, a third-party extension (https://terragotech.com/resources/sample-geopdfs/ https://terragotech.com/resources/sample-geopdfs/) that don't work right at all outside of Acrobat, even though they're used by the USGS (https://www.usgs.gov/faqs/what-geopdfr https://www.usgs.gov/faqs/what-geopdfr). It's kinda like the Word doc situation of the 2000s... third-party utilities can usually open them and get the basic document and formatting, but not perfectly, and some features just won't work.

eternityforest 3y ago
Why is the government using non standard features? Did they make it back when people actually used Acrobat?
- deleted 3y ago
  [deleted]
- solardev 3y ago
  Hey, give them some credit... at least they upgraded from fax machines a few years ago... ;) ------- Edit: Less snarkily, I think there just aren't a lot of bleeding-edge tech people in civil service, at least in the US. Would you want to give up your cushy dev job to work for a huge bureaucracy at maybe 40% of the industry pay? So you're left with bureaucrats/administrative workers who grew up on MS Office and Adobe Acrobat, and who can't easily switch to new tools even if they wanted to without a horribly complicated purchasing process. Some other countries and small localities experimented with replacing MS Office with OpenOffice, for example, or Windows with Linux but I think most of those failed. Similarly, most government geographical services use ESRI software even though open-source ones have been around for a while. Sometimes it's a matter of feature parity, but more likely than not, only big entities like that are equipped to deal with government contracting and support. Government moves really, really slow, and prefers to work with other huge companies under really complex contracts... it's antithetical to most software/web work. Nobody is going to jump through all those hoops just to get us a slightly more standard PDF form. If you push them too hard they'll probably just go back to paper forms and fax, lol.

j4hdufd8 3y ago

Surely someone has reverse engineered it and open sourced it?

rstuart4133 3y ago

It misses at least one editing tool, which happens to be the one I prefer: xournal. https://xournalpp.github.io/guide/pdfs/ https://xournalpp.github.io/guide/pdfs/ LibreOffice's apps and Inkscape also do the job as they say, but they re-render the existing content which often changes it's look. In particular of it don't have a close matching font installed the result can be a mess. xournal doesn't have that problem but it only lets you add, not delete or modify. No mention of digital (x509) signing. LibreOffice can do it - but see above. Okula can do it reasonably well, if you are prepared to pollute your Firefox certs with your personal ones. I haven't found a command line tool (like pdftk) that does it, which is sad.

gettalong 3y ago
If you need a state of the art CLI tool for signing PDFs that supports the latest standards (think ones from 2023), I can recommend pyHanko (https://github.com/MatthiasValvekens/pyHanko/ https://github.com/MatthiasValvekens/pyHanko/).
- rstuart4133 3y ago
  Thank you. Responses like these make HN awesome.

egberts1 3y ago

Thr short answer is no. Embedding JavaScript is security mistake #1. Placing references at the end of the file is data-extensibility mistake #2. Auto-executing embedded URL is security mistake #3 Disclaimer: I write high-speed PDF parsers for various IDS/XNS/IPS companies.

gettalong 3y ago

It seems that the news hasn't spread far yet but due to sponsorships by various big PDF related companies the ISO standard for PDF 2.0 is freely available, see https://www.pdfa-inc.org/product/iso-32000-2-pdf-2-0-bundle-sponsored-access/ https://www.pdfa-inc.org/product/iso-32000-2-pdf-2-0-bundle-... While the PDF 1.7 spec from Adobe was always available, once it was turned into an ISO spec (ISO 32000-1:2008) it became paywalled. Due to an agreement with Adobe, the ISO version of the PDF 1.7 spec was made available free of charge. However, the further development of the PDF standard was done according to ISO rules and that meant paying for the standard... until the PDF association and a few companies stepped up and made the spec free again (also see https://www.pdfa.org/sponsored-standards/ https://www.pdfa.org/sponsored-standards/).