Firefox 41 will be the last version because of the plugin system (Score: 0) by Anonymous Coward on 2015-08-29 04:31 (#JSRK) "Starting with Firefox 42, developers will also have to get their extensions reviewed and signed by Mozilla before they can be deployed. "" I had a situation at work where some software used two years ago was needed today to redo some work. No problem, as I have a folder with the software. Pulled it out, installed the plugin on Chrome..NO! NO PLUGIN FOR YOU!. Okay. This is in a dev environment so is firewalled from the internet. After a few tries I gave up on Chrome. It just can't be used to install plugins locally. No, I am not screwing around with unpacking and repacking extensions. I pulled up Firefox, installed the plugin, and was good to go. Work was done. Reports were filed. Everyone is happy. After Firefox 42 this will not be possible. If I had Firefox 42 in the dev environment right now, and no previous versions of the browsers, I would be screwed. Now, what happens if I am testing for compatibility in a future version of Firefox or Chrome? What then? At what point do we admit that locking out local installs of plugins is a bad thing?