GlassAMP for Winampback
Windows 2000 has layered windows. They're pretty buggy.
Warning: Please do not run this unless you have Windows 2000 or later.
If you don't care about C++ code, you can just get the GlassAMP installer [40k].
Otherwise, here's the source and DLL: Download: genalpha.zip [10kb] [source + .DLL].
You need the Windows Platform SDK if you want to compile this for yourself.