For some time now Firefox has supported a way of installing extensions that involves simply copying the extension’s XPI file into one of the extension install locations. The next time Firefox runs it would pop up the install dialog for the extension and allow the user to choose whether to install it or not.

I don’t know how many people use this feature and while the code to do it (at least for the profile folder) isn’t terribly complex, it is additional code that may not be necessary. Right now the new add-ons manager doesn’t support it and I’ve heard only a couple of people comment on its absence but nightly testers are by no means representational so I’m asking a little more widely whether people have a real need for keeping this working in Firefox 4?

To be clear we aren’t talking about the method of installing where you extract your extension into a directory in the install locations, nor are we talking about the method where you create a text file in the install location containing the path to your extension.