<script> is HTML 5.
Is it different for different webservers?
That isn't the case. Something else must have been wrong with your test case.
Douglas Crockford says:
This attribute is optional. Since
Netscape 2, the default programming
language in all browsers has been
is required and unnecessary. In HTML,
it is better to leave it out. The
browser knows what to do.
In HTML 4.01 and XHTML 1(.1), the
type attribute for
<script> elements is required.
<!-- HTML4 and (x)HTML -->
<!-- HTML5 -->