The simple answer is yes it is - it will still work in new browsers for a while yet but if you are making code aimed at working in the future then you should start moving away from the <APPLET> tag. The following code will work in most browsers:
code:
<object classid="clsid:8AD9C840-044E-11D1-B3E9-00805F499D93"
codebase="http://java.sun.com/products/plugin/1.4/jinstall-14-win32.cab#Version=1,4,0,mn"
width="WIDTH"
height="HEIGHT"
align="baseline">
<param name="code" value="FILE NAME">
<param name="codebase" value="PATH TO FILE">
<param name="type" value="application/x-java-applet;jpi-version=1.4">
<comment>
<embed code="FILE NAME"
codebase="PATH TO FILE"
type="application/x-java-applet;jpi-version=1.4"
width="WIDTH"
height="HEIGHT"
align="baseline"
pluginspage="http://java.sun.com/products/plugin/1.4/plugin-install.html">
<noembed>
No Java 2 SDK, Standard Edition v 1.4 support for APPLET!!
</noembed>
</embed>
</comment>
</object>
