The embed tag is for older browsers that do not
support the W3 specification for the <object> tag
which is the now most supported and recommended option
for embedding QTVR. For example as of IE5.5 SP2, the
embed tag is no longer supported at all, yet Netscape
6 still can use it....
Typically you use both by nesting them. Browsers that
can use the <object> tag will ignore the <embed> and
older browsers that don't use the <object> tag will
use the <embed> and ignore the <object>. The most
simplest version of this combined structure should
look something like this (Apple also recommends this):
<OBJECT
CLASSID="clsid:02BF25D5-8C17-4B23-BC80-D3488ABDDC6B"
CODEBASE="http://www.apple.com/qtactivex/qtplugin.cab";
WIDTH="xx" HEIGHT="yy">
<PARAM NAME="src" VALUE="my.mov">
<EMBED SRC="my.mov" height="yy" width="xx"></EMBED>
</OBJECT>
Hope this helps