Can you get a list of Firefox add-ons programmatically

Question

I spent a fair amount of time trying to determine why my view of a site didn't match a clients, after looking at the cache etc. we determined the problem to be with one of the add-ons (Adblock Plus in this particular case). It would have been much simpler if we could have had an easy way to query what add-ons were installed, and ideally active. Is there anyway to generate a list programmatically perhaps with JavaScript?

Answer 1

No, you can't do this with user/page JavaScript. I imagine it would be a security risk, if you could.

But there is an add-on you can install that will generate a printable, copyable list of installed extensions/Add-ons.

Check out: "Extension List Dumper".

Answer 2

You cannot get a complete list just by using Javascript, but some Addons allow a check anyway.

accessing the chrome://-protocol was considered a security risk and therefore has been disabled. Nonetheless you can still accomplish to detect an extension with the image-load trick. Why? Because extension developers may mark their extension as web-accessible setting the property “contentaccessible=yes” inside the chrome.manifest file of the extension. This is e.g. the case for the two famous plugins Firebug and Web Developer Toolbar

source: http://webdevwonders.com/detecting-firefox-add-ons/