+1  A: 

Simple answer is that IE doesn't support the type value of application/javascript. The RFC 4329 which recommends it obviously came after the release of IE6, I guess the MS developers didn't feel the need to even support the MIME type.

meder  2009-08-17 14:33:41
Indeed. There's some discussion about whether that should change, but obviously that would make it easy for developers to inadvertantly build sites that don't work in 60+% of the world's browsers.
EricLaw -MSFT-  2009-08-17 14:40:26
Recently already a bit less than 60% of the world's browsers. Yay!
macbirdie  2010-05-05 09:35:03
+3  A: 

"text/javascript" is the only type that is supported by all three browsers. However, you don't actually need to put a type. The type attribute of a script tag will default to "text/javascript" if it is not otherwise specified. How that will affect validation, I'm not sure. But does that really matter anyway?

geowa4  2009-08-17 14:38:28

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