a few weeks ago I stumbled over a javascript that you can add to your site, and it would automatically modify your css, to work around some bugs in browsers, and add features they don't support (e.g. drop shadow)
Now I can't find it anymore. I found http://css3pie.com/ but that's not it.
Any hints?
Probably Modernizr - from their documentation page:
Modernizr is a small JavaScript library that detects the availability of native implementations for next-generation web technologies, i.e. features that stem from the HTML5 and CSS3 specifications. Many of these features are already implemented in at least one major browser (most of them in two or more), and what Modernizr does is, very simply, tell you whether the current browser has this feature natively implemented or not.
Sounds like you are looking for Modernizr; out there are a lot of this scripts that simulate a few css properties. For example, if I'm going to develop something in HTML5, I use the HTML5 shim because IE7 and IE8 doesn't support HTML5 tags:
<!--[if lt IE9]-->
<script src="http://html5shim.googlecode.com/svn/trunk/html5.js"></script>
<![endif]-->
You may be thinking of Prefix-Free, which came out a few weeks ago. It doesn't work around browser bugs per se, it allows you to write one CSS3 rule and it adds vendor prefixes where possible. Also known as a "polyfill".
