Applets can be incorporated just like images. Witness for example:


(drag the bouncy ball)

This is the code:

<applet height=180 width=400 codebase="http://www.ooi.com/exploringjava/" code=ooi>
        <param name=logoImage value="http://www.ooi.com/exploringjava/images/ej.gif">
        <param name=shadowImage value="http://www.ooi.com/exploringjava/images/ej_shadow.gif">
        <param name=ballImage value="http://www.ooi.com/exploringjava/images/ball.gif">
        <param name=ballSquishXImage1 value="http://www.ooi.com/exploringjava/images/bsx1.gif">
        <param name=ballSquishXImage2 value="http://www.ooi.com/exploringjava/images/bsx2.gif">
        <param name=ballSquishYImage1 value="http://www.ooi.com/exploringjava/images/bsy1.gif">
        <param name=ballSquishYImage2 value="http://www.ooi.com/exploringjava/images/bsy2.gif">
        <param name=startx value="20">
        <param name=starty value="20">
        <param name=xpad value="50">
        <param name=ypad value="30">
<img src="http://www.ooi.com/exploringjavaimages/ej.gif">
</applet><br>
The Real Thing (Explore Java at O'Reilly)