Thanks for trying to popularise this cool feature. But IE and Mozilla-based browsers work I think in the same way, not the different way you say here – you shouldn’t need to handle them separately, although you will obviously want to handle (or avoid handling) other browsers

You can use the javascript window.external.AddSearchProvider in Firefox2.0+

Or you can use the link style in Internet Explorer 7+

See http://www.oxan.com and then look at the list of search engines – ours will show up with a * and can be installed, in both IE7 and Mozilla-based engines.