• text/javascript – is obsolete
• application/x-javascript – was experimental while deciding to move to …
• application/javascript is the current official MIME type for JS

That said, browsers ignore the content-type sent by the server and pay too much attention to the type attribute (and many don’t yet recognise application/javascript).

My recommendation:

• Use application/javascript on the server
• Use text/javascript as a hack in type attributes in HTML documents

text/javascript已经过时,

application/x-javascripts是实验性的,

application/javascript 是js文件正式的MIME类型.

text/xml和application/xml有什么不同？

XML has two MIME types,application/xml and text/xml . These are often used interchangeably, but there is a subtle difference which is why application/xml is generally recommended over the latter.

Let me explain why: according to the standard, text/* -MIME types have a us-ascii character set unless otherwise specified in the HTTP headers. This effectively means that any encoding defined in the XML prolog (e.g. <?xml version=”1.0” encoding=”UTF-8”?>) is ignored. This is of course not the expected and desired behaviour.

To further complicate matters, most/all browser implementations actually implement nonstandard behaviour for text/xml because they process the encoding as if it were application/xml .

So, text/* has encoding issues, and is not implemented by browsers in a standards-compliant manner, which is why using application/* is recommended.