Obsolete This feature is obsolete. Although it may still work in some browsers, its use is discouraged since it could be removed at any time. Try to avoid using it. Quite a lot has happened since this article was written. E. g. in Firefox 3, a cycle collector was introduced and refined in later versions, and Mozilla is currently working on a generational garbage collector for JS. This article need
![Avoiding leaks in JavaScript XPCOM components - Mozilla | MDN](https://cdn-ak-scissors.b.st-hatena.com/image/square/93d09855fe809a1603c1a7e744962280e02863f1/height=288;version=1;width=512/https%3A%2F%2Fdeveloper.mozilla.org%2Fmdn-social-share.2f09512a.png)