What is "pdf.js"

PDF.js or pdf.js is a JavaScript library intended to render PDF files using the HTML5 Canvas for a safer and web standards compliant web browser rendering of PDF files. The project is led by the Mozilla Foundation after Andreas Gal launched it (initially as an experiment) in 2011.

PDF.js can work as a part of a website or of a browser. Originally created as a Firefox extension it is now included in Mozilla Firefox since 2012 (version 15), and is enabled by default since 2013 (version 19). SeaMonkey users need to install the development version of the extension. It is also part of ownCloud and there exists a Chrome/ Chromium (web browser) plugin.