Is there a way to escape a loop like the one below without closing the browser by terminating it process?
WARNING: Don't run the code below. Running this code will throw your browser in an infinite loop of alerts.
<html><body onload="while(true)alert('Hello')"></body></html>
Some browsers will disallow this from happening in the first place.
Whenever this does happens to me, I do my best to do the following key sequence quickly:
[ENTER] Ctrl+W
Which will escape the loop and close the window/tab, but shouldn't terminate the browser.
EDIT I shouldn't say it escapes the loop. It closes the window which prevents that page from executing anymore javascript.
On Firefox, install the Firebug plugin. Among many other useful features, it allows you to debug javascript code.
Firebug plug-in for FireFox, mentioned in another answer, is one, albeit overly-powerful, option.
A more targeted one is an AlertCheck plug-in.
Here's a screenshot of the checkbox it adds to alert dialogs:
For non-FireFox browsers, there's no generic answer aside from really quick Ctrl+W after clicking/ENTER-ing "OK" which is hard to make work (and may not work on Internet Explorer 6 which IIRC doesn't do Ctrl-W).