pdf.js is a Firefox extension being developed by Mozilla Labs which uses HTML5 to display PDF files within Firefox without the need of a PDF browser plugin such as Adobe Reader or FoxIt Reader (note: you will still need one of these readers to view local/downloaded PDF files). This extension is still experimental and in development, but appears to be fairly stable. Once install it is ready to go without a browser restart, but you will need to disable any other PDF related plugins/extensions.This add-on works with Firefox 7.0 thru 10.0a1 builds.
