JS cross browser inconsistencies/differences
<p>There are lots of DOM/CSS inconsistencies between browsers. But how many core JS differences are there between browsers? One that recently tripped me up is that in Firefox, setTimeout callback functions get passed an extra parameter (https://developer.mozilla.org/en/window.setTimeout). </p>

<p>Also, now that browsers are implementing new functions (e.g. Array.map), it can get confusing to know what you can/can't use if you are trying to write code that must work on all browsers (even back to IE6). </p>

<p>Is there a website that cleanly organizes these types of differences? </p>
