From Firefox 40 will be dropped support for binary XPCOM components - so another piece of history on which I started "real" programming will be gone. Some of you maybe remember XPCOMViewer :)
You can see more details here: https://blog.mozilla.org/addons/2015/05/04/dropping-support-for-binary-components/ and here https://groups.google.com/forum/#!topic/mozilla.dev.extensions/B3H3j6FRVms
