Firefox has been depreciating extensions and native add-ons in favor of high level JS add-ons; and moving away from Adobe flash and NNAPI support. All this is culminating in making it difficult to support Microsoft ClickOnce applications on FireFox (and Chrome) platforms. There are two issues at hand: 1/ To launch an application that will initiate the ClickOnce .NET launcher 2/ To launch the installed application Both from the web application. To put this into context the business application launches a scanning device for a Saas application. I have been using Microsoft Net Framework Assistant extension for many years and recently Firefox admin has removed it. To further compound the problem; Chrome and Firefox are both dropping NNAPI: 3/ How to launch on the OSX platform (not a Click-Once app) Chrome (yes I know this is a Firefox forum) is going PPAPI. Firefox has no plans for PPAPI - stating that WebAPI should be sufficient for mime support. However, in context of Click-Once I am not sure. So, I am reaching out to you. I am a developer and am not adverse to writing my own solution if you can point me in the right direction for the technologies I need to use. Any advice and support will be greatly appreciated. The question simply put: How can I launch a Click-Once package from within a Firefox hosted web page and have it install and launch the application? I am OK with asking the user to install an extension/plugin/add-on (but given the industry - this will either have to be a commercial solution or one I write).