Greetings webkit-dev, It's generally agreed upon in the web community, and in WebKit specifically, that DOM Mutation Events are a bad thing. See, e.g., discussion on https://bugs.webkit.org/show_bug.cgi?id=8191 (relating to DOMAttrModified, and why WebKit does not wish to implement it) and https://lists.webkit.org/pipermail/webkit-dev/2010-August/013805.html (a discussion of replacing DOM mutations with something better, or removing them entirely). In late June, Jonas Sicking and Olli Pettay from Mozilla put forward proposals on public-webapps (http://lists.w3.org/Archives/Public/public-webapps/2011AprJun/1318.html) to replace mutation events with a different API, one that avoids the problems associated with the existing spec. Rafael Weinstein has helpfully summarized the public-webapps thread (which is now upwards of 200 messages long) in http://lists.w3.org/Archives/Public/public-webapps/2011JulSep/0779.html, and discussion is ongoing in http://lists.w3.org/Archives/Public/public-webapps/2011JulSep/0780.html. Any WebKit folks interested in the future of mutation events in the DOM are invited to join that discussion, and their input would be much appreciated. I've also put together a partial implementation of Jonas' most recent proposal and uploaded my work-in-progress patch to https://bugs.webkit.org/show_bug.cgi?id=66079. Note that this is very early work, and if I were submitting it for review it would be in much smaller chunks, but I welcome any comments or questions on the code as-is. - Adam