I've been working with my company for about half a year now, and we've constantly been fighting with clients on upgrading their browsers. Everyone is of the mind that moving to a newer browser is only going to introduce more problems than solutions (they have internal, old web applications designed for in-house work)

I'm at the point where I've had to hunt down and polyfill so many things with IE8 that I'm wondering if there is any draw-back to polyfilling every deficiency that IE8 has (or at least making it so that the javascript doesn't error/fail)


Is it unreasonable to expect to be able to polyfill all of the deficiencies in older outdated browsers such as IE6-IE8, or would that be a bad idea (performance? stability?)...

If this is a possibility, how come there are no full-feature polyfill libraries, everyone will point to "modernizr", that is FEATURE DETECTION, and offers no polyfills of it's own.


So, wheres the IE8 master/full polyfill library hiding, or am I gonna have to slave over this?


Edit: the reason why I'm not just picking out the parts I need, is because there might be deficiencies we are not aware of, I'd love to have a fix-all for Internet Explorer, so if this doesn't exist I'm going to make it myself.