Tutorial 16: Client-Side Scripting 101 - HTML with Style | 5
You should always specify both the MIME content type of the script and the language the script is in. Although the LANGUAGE attribute is deprecated, you should use it because older browsers do not recognize the TYPE attribute.
The values accepted by the LANGUAGE attribute are mostly browser-dependant. The purpose of both the LANGUAGE and TYPE attributes are to allow browsers that don't support a particular scripting language to ignore the particular script. So, for instance, if a browser doesn't grok the "FooScript" language, it would ignore the following script:
<SCRIPT TYPE="application/x-fooscript" LANGUAGE="FooScript" SRC="http://www.acme.com/scripts/bar.fs" > </SCRIPT>
Produced by Stephanos Piperoglou
Created: September 15, 1999
Revised: September 27, 1999