You can find documentation about the core of PDF.js here (contributed by user MeiKatz).

You can read more about PDF.js here:

• https://andreasgal.com/2011/06/15/pdf-js/
• https://web.archive.org/web/20160408133647/https://blog.mozilla.org/cjones/2011/06/15/overview-of-pdf-js-guts/
• https://blog.mozilla.org/attack-and-defense/2021/10/14/implementing-form-filling-and-accessibility-in-the-firefox-pdf-viewer/

Videos:

• Julian Viereck – Zurich GTUG 2011, https://blog.mozilla.org/labs/2011/10/video-what-is-pdf-js/
• Brendan Dahl – HTML5DevConf 2013, https://www.youtube.com/watch?v=4yLzRoErOHw
• Mack Duan – Optimizing PDF.js, Mozilla, 2013, https://air.mozilla.org/intern-pdfjs/

Slides:

• https://jviereck.github.com/slides/2012_07_berlinjs/index.html
• Yury Delendik – TTF 2012, Evolving with Web Standards. The Story of PDF.JS.
• Brendan Dahl – HTML5DevConf 2013, https://brendandahl.github.io/speaking-events/2013-html5-dev-conf

A really basic overview of PDF is described here:

• https://web.archive.org/web/20150218210352if_/http://partners.adobe.com/public/developer/en/livecycle/lc_pdf_overview_format.pdf

Summary of the PDF file format:

• https://web.archive.org/web/20180211042516/https://planetpdf.com/developer/article.asp?ContentID=navigating_the_internal_struct

The PDF specification:

• https://www.adobe.com/devnet/acrobat/pdfs/PDF32000_2008.pdf

Presentations:

• https://labs.appligent.com/files/2013/03/recognizing_malformed_pdf_f.pdf

• https://github.com/mozilla/pdf.js/tree/master/examples/learning
• https://github.com/mozilla/pdf.js/tree/master/examples/components

Open source projects:

• https://poppler.freedesktop.org
• https://www.mupdf.com