This does not affect scripting contained within script tags, but provides a way to select a script language interpreter for use with event handlers for example.
The following scripting languages are supported in MSIE (Netscape does not support this facility):
The values are case-insensitive in the MSIE browser.
With this property available, it is conceivable that other languages could be supported in the future. For example, client-side Perl and Python are feasible. Search out the PerlScript and ActivePython projects for further details.