GitHub repositories
The PDF Association hosts many public and private repositories in GitHub to facilitate a common understanding of PDF and for developing new ideas around PDF technologies.
Public repositories welcome contributions and comments from anyone under the terms of the Agreement to Participate. Private repositories are restricted to PDF Association members.
Public repos
PDF errata – pdf-issues
This public repository provides developers with a way to openly report and discuss technical errata with PDF-related specifications or ISO publications. All issues in PDF technical specifications are important, from minor typos and formatting issues to larger, ambiguous, unclear, or potentially contradictory statements. By communicating consensus on industry resolutions, PDF interoperability and implementation reliability can be improved.
This repo is coordinated by the PDF Technical Working Group and supports errata logged against PDF Association industry specifications and ISO publications related to PDF, including:
- PDF 2.0 (ISO 32000-2:2020), including all PDF 2.0 ISO Technical Specifications (TS) extensions and clarifications.
- PDF/A series (ISO 19005 series)
- PDF/X-6 (ISO 15930-9:2020) and PDF/VT-3 (ISO 16612-3:2020)
- ECMAScript for PDF 2.0 (ISO 21757-1:2020)
- XMP metadata (ISO 16684 series)
- Well-Tagged PDF
- PDF Declarations
report-an-issue
Anything you want to report about a PDF Association publication, resource, or website? This is the place for you.
arlington-pdf-model
The Arlington PDF Model is an open source specification-derived, machine-readable definition of the full PDF document object model (DOM) as defined by the PDF 2.0 specification ISO 32000-2:2020 and its related resolved errata. It provides an easy-to-process, structured definition of all formally defined PDF objects (dictionaries, arrays, and map objects) and their data-integrity relationships, beginning with the file trailer, using a simple text-based syntax and a small set of declarative functions. The Arlington PDF Model is applicable to both PDF readers and PDF writers.
pdf-differences
The PDF files in this repository are targeted test files that highlight specific non-conforming functionality or rendering issues observed across multiple widely used implementations. Security-related issues are not included, and implementations will not be named or identified. PDF Association members get a 60-day preview of all new differences before the public announcement via the private repository pdf-differences-preview.
pdf20examples
This is a collection of example PDF 2.0 files that comply with ISO 32000-2:2020. The files in this collection are intended for educational purposes and are intentionally kept relatively simple and human-readable. Each example illustrates the usage of a new PDF 2.0 feature.
techniques-for-accessible-pdf
This repo contains the PDF Association's Techniques for Accessible PDF as published on pdfa.org. The contents of this repo are intended primarily for developers, whereas the same content is presented in a friendlier manner on pdfa.org.
Anyone can post an Issue in this repo as a public comment on the posted Techniques or to suggest additional Techniques. All issues are reviewed by the PDF Association's PDF Accessibility Liaison Working Group.
PDF-RichMedia-Annotations
Repository for PDF 2.0 RichMedia annotation documentation, based on ISO 32000-2:2020. It is overseen by the PDF Association's Rich Media TWG.
pdf-declarations
This repo contains a JSON definition and schema for all PDF Declarations registered with the PDF Association and as published on this page: https://pdfa.org/declarations/. PDF Declarations are XMP metadata used to express conformance to third-party specifications, according to the PDF Declarations specification.
pdf-extensions
This repo contains a JSON definition and schema for publicly defined PDF extensions registered with the PDF Association and as published on this page: https://pdfa.org/extensions/.
pdf-corpora
This index references a number of the more significant public corpora (data sets) that may contain both valid and invalid, real and synthetic PDF files, reflecting the realities of processing PDF files 'from the wild. In addition, targeted test suites for specific PDF features, ISO subsets of PDF, and some of the nested formats used inside PDF files are also listed. It is not intended to be a list of every website where PDFs may be obtained.
Private repos (publications)
Joining private GitHub repositories requires both PDF Association and working group membership.
appnote-custom-metadata
This repository is for authoring and further development of the Metanorma (AsciiDoc) sources defining the “Application Note: Including custom metadata structures in PDF”. It is overseen by the PDF TWG.
appnote-faq-hdr
This repository is for authoring and further development of the Metanorma (AsciiDoc) sources defining the “Application Note: FAQ on HDR in PDF: Focus on PDF/A and PDF/X”. It is overseen by the PDF TWG.
appnote-pdf20-001-bpc
This repository is for the authoring and further development of the Metanorma (AsciiDoc) sources defining “PDF 2.0 Application Note 001: Usage of Black Point Compensation”. It is overseen by the PDF TWG.
appnote-pdf20-002-af
This repository is for the authoring and further development of the Metanorma (AsciiDoc) sources defining the “PDF 2.0 Application Note 002: Associated Files”. It is overseen by the PDF TWG.
appnote-pdf20-003-metadata
This repository is for authoring and further development of the Metanorma (AsciiDoc) sources that define “PDF 2.0 Application Note 003: Clarification on locations for object metadata streams”. It is overseen by the PDF TWG.
bpg-conforming-pdfa-pdfua
This repository is for the authoring and development of the AsciiDoc source files for “Best Practice Guide: Conforming to both PDF/A and PDF/UA”. It is jointly overseen by the PDF/A TWG and PDF/UA TWG.
bpg-tagged-pdf-syntax
This repository is for the authoring and development of the AsciiDoc source files for “Tagged PDF Best Practice Guide: Syntax – For developers implementing ISO 14289-1 (PDF/UA)”. It is overseen by the PDF/UA TWG.
Deriving-HTML-from-PDF
The repository tracks work on updates to the document describing the algorithm for Deriving HTML from well-tagged PDF 2.0 (as defined by ISO 32000-2:2020). It is overseen by the Deriving HTML from PDF TWG.
extension-brotli
The repository is for authoring and development of the Metanorma (AsciiDoc) sources that will define the Brotli compression extension to ISO 32000-2 (PDF 2.0). It is overseen by the PDF TWG.
extension-pqc
The repository is for authoring and development of the Metanorma (AsciiDoc) sources for future post-quantum cryptography extensions to ISO 32000-2 (PDF 2.0). It is overseen by the Cryptography and Provenance TWG.
nutshell-pdf-ua
This private repository is for the authoring and development of an updated “PDF/UA in a Nutshell” publication. Overseen by the PDF/UA Marketing Working Group (MWG).
PDFPath
This private repository is for the authoring and development of a new technology specification tentatively called “PDF Path”, as a proposed common syntax similar to what XPath is for XML. Overseen by the PDF TWG.
rfc-application-pdf
This private repository is for the authoring and development of an updated RFC to replace RFC 8118, “The application/pdf Media Type”. It uses Metanorma (AsciiDoc) to author an IETF RFC-style document. Overseen by the PDF TWG.
spec-pdf-declarations
This repository is for the authoring and further development of the AsciiDoc source files for “PDF Declarations: A use of ISO 32000”. It is overseen by the PDF TWG.
spec-tag-tree-diagrams
This private repository contains the Metanorma (AsciiDoc) source for the “PDF Tag Tree Diagrams” specification, defining how to consistently diagrammatically represent hierarchical logical structure trees (or portions) using PlantUML “salt” tree table diagrams in PDF Association publications. Overseen by the PDF Reuse TWG.
technote-pdfua1-001
This private repository is for authoring and developing the Metanorma (AsciiDoc) sources defining the “PDF/UA-1 Technical Note 001: Use of ActualText & Reference tags”. It is overseen by the PDF/UA TWG.
WTPDF
This repository is for authoring and developing the Well-Tagged PDF specification. It is overseen by the PDF Reuse TWG.
Private repos (Working Groups)
3dpdf-twg
crypto-provenance-twg
forensics-lwg
latex-project-lwg
pdfa-twg
Pdf-forms
pdfua-twg
reuse-twg
techniques-for-accessible-pdf-lwg
Other repos
corpus-compression
This private repository contains corpora and results related to future PDF compression features, including new compression filters, new methods for expressing content streams, new streaming methods, etc. Overseen by the PDF TWG.
DARPA SafeDocs repos
Artifacts from the DARPA-funded SafeDocs research program are across several public repositories: safedocs (including the compacted syntax tests as described in this article), pdf-cos-syntax (our Visual Studio Code “pdf-cos-syntax” extension), and PDF2NormRefs (an analysis of the full normative references tree from ISO 32000-2:2020, as visualized here).