Hi jglick,
Now that css3 is almost main stream, is it OK to remove IE filter from style.css?

@evernat perhaps; I really have no idea what this particular entry is for, or which versions of IE need it. (I know people still routinely use Jenkins with IE 9, maybe even 8.) In any event, my original suggestion of splitting browser-specific entries into dynamically inserted stylesheets would suppress the test warnings and probably also suppress warnings from modern browsers which no longer require the hacks.

after a google search,

• opacity: 0.5; works since IE9 and in all modern browsers.
• filter: alpha(opacity=50); works for IE8 and before
• -ms-filter: "progid:DXImageTransform.Microsoft.Alpha(Opacity=50)"; also works for IE8 and before

IE8 is certainly used only by users still having Windows XP, because they can't upgrade to IE9. But Windows XP is EOL and not supported anymore since yesterday. So IE8 usage will now drop fast like Windows XP usage.

So I think that we can remove both -ms-filter and filter: alpha lines.

FWIW, a quick (~3min) search of support tickets from CloudBees customers reveals five companies (before I stopped counting) who are using IE 8 to access Jenkins. Some of these explicitly state (by way of apology) that IE 8 is the corporate IT mandate. So I doubt we can drop support for it so casually. Of course inessential aspects of its rendering could be skipped so long as the page view is still functional, if that simplifies the CSS.

Forcing usage of a dinosaur like IE8, would need apologies indeed, even on the now officially dead Windows XP.

I think Tom is best placed to work on this at the moment.