Dean Edwards IE7

Web site: http://dean.edwards.name/IE7/

License: LGPL

Dean Edwards IE7 is a browser-compatibility library that uses JavaScript to extend Internet Explorer 5 and 6, giving these browsers support for newer CSS standards. It also fixes various layout bugs and contains a fix for transparent PNGS. It works quite well and can be an easy addition for a site that is targeted toward a standards-compliant browser that later needs to be made to work in IE. On large and complex sites, IE7 can add some additional load times and can cause page reflows after the initial layout is done. However, if you use IE7 enough to understand its drawbacks, it can be a useful tool for supporting IE6.