http://trac.webkit.org/wiki/WebKit2 This page is out-of-date, at least in this sentence (C API section): "This can useful when access to the DOM is required. [Planned, but not currently implemented]". Carlos explains how to achieve this in his blog post "WebKit2GTK+ Web Process Extensions" [1]. Could you link to this article from wiki? Maybe current status is also outdated, in section Current Status. "an early technology demo". [1] http://blogs.igalia.com/carlosgc/2013/09/10/webkit2gtk-web-process-extensions/