Quote of the day is about Chrome and features

Per-process execution is a feature in Chromium (Google Chrome), not V8. And it is really needed anyway if one is using V8, because V8 is not thread safe.

So that is why you have one process for Tab in chrome (it's a bug called feature in V8)

Via trolls labs

http://labs.trolltech.com/blogs/2009/06/16/using-javascriptcore-as-the-qtscript-back-end/