Online one can find links to the reference implementation of ECMAScript 4 (which was eventually abandoned for Harmony). However, all these links seem to have bitrotted and, because of an interstitial form, the archive of the download doesn't include the tarball ( https://web.archive.org/web/20070712063844/http://www.ecmascript-lang.org/download.php ).Does anyone happen to know a way to access this source code for research purposes?