I'm using firebreath to build a plugin that downloads an application and runs it (something very simple). I know that some browsers are dropping npapi support, but I need to run this plugin just in old versions of browsers (e.g. IE 6, Firefox 38, Chrome 31). I'd like to know if there are any tools that could help testing the plugin's in a variety of environments (e.g. Firefox on Linux,windows, Safari on OSX). So far, what I'm doing, is setting up each environment (windows, linux, Mac) and building/installing the plugins manually. I think cross browser testing tools that I've found on internet won't help, because they don't allow plugin install.
I couldn't find anything on my research, so thanks in advance
Any browser automation tool capable of instrumenting pages on all of those platforms can test NPAPI, since it runs in a browser...
so, Selenium, for example.