When I try to use APPLET I get swiggly line under it. A Tip tool says that "WWW considers the element 'APPLET' as outdated. New constructors are recommended"

What can I use?

I tried to use applet:
<APPLET code=ArtistscopeViewer.class width=253 height=318 name=Artistscope000 id=Artistscope VIEWASTEXT>
<param name="style" value="ImageImage">
<param name="textColour" value="ffffff">
<param name="borderColour" value="000000">
<param name="border" value="0">
<param name="loading" value="Loading...">

<param name="label" value="Artistscope - Developed by Artists for Artists">
</APPLET><BR>

Thanks
<APPLET code=ArtistscopePro.class width=1 height=1 name=ArtistscopePro id="Object1" VIEWASTEXT>
<param name="ViewerCount" value="1">
<param name="FrameCount000" value="2">
<param name="000000" value="6_p1.class">
<param name="000001" value="6_p1.class">
</APPLET>

Is this meant for ASP.NET?