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Comment by flavio81 | Hacker News Reader

TL:DR; They have written a PS & PDF renderer that runs completely in the client, by using web-assembly. They show the performance to be not so far off using native code, and this allows offloading the CPU load of PDF rendering to the client rather than the server.

Excellent !!

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Correction: last I checked, they didn't write the PDF renderer themselves, it is Google's PDFium[1] which was open-sourced a while ago. Before they were using Apple's built in PDF engine, but apparently that had too many bugs for them.

It does not do Postscript, the "PS" in PSPDFKit are the initials of the creator, Peter Steinberger (really nice guy, by the way!). Two/three letter prefixes are common in Objective-C as there are no namespaces (I use MPW).

[1] https://pdfium.googlesource.com

Thanks, i thought PS stood for "postscript"!

Based on Peter's blog post[0] a few years ago, I was under the impression they wrote their own.

Maybe steipete can chime in?

[0]https://pspdfkit.com/blog/2016/a-pragmatic-approach-to-cross...

Hmmm...don't remember where I got that information from, so I could well be remembering wrong.

I do see that pspdfkit folk are active in the pdfium bug tracker, for example:

https://bugs.chromium.org/p/pdfium/issues/detail?id=641

That sounds like a production problem, but it could just as well be them trying it out.

It's certainly quite plausible that they compare their behavior with other engines, and then file bugs on those other engines if they find them.

mpweiher, you are correct! PSPDF is a pdfium lipstick. You can find its license in binary sdk-s or simply ask them. Included or derived work must be disclosed!

Also using the pdfium via Enscripten is not news (https://github.com/coolwanglu/PDFium.js is 3 years old).

On commercial, battle tested side PDFTron offers PDFNetJS & WebViewer for years https://blog.pdftron.com/2015/11/10/pdfnetjs-html5-pdf-viewe... (http://xodo.com/app is the demo referenced in the presentation).

My latest laptop is from 2009 and I very very very rarely complain about pdf.js performance.

If anyone has any questions I'll try and answer if I can.

Did you show it to Mozilla or Google? It seems that it can replace PDF.JS and whatever closed-source PDF reader chrome uses.

Chrome's PDF reader is actually open-source: https://pdfium.googlesource.com/pdfium/

Sorry. I'm out of date https://bugs.chromium.org/p/chromium/issues/detail?id=50852#...

And as far as I know it's the engine they're using.

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