WACUP = WinAmp Community Update Project
Download & Info | Changelog (x86) or (x64)
If you want full plugin compatibility use the x86 version.
Sometimes I use old visualization plugins in my workout room. Here are the plugins I’m running now:

Vis_Mux doesn’t work anymore but multiple plugins at once supported.

If you have really old plugins that you want to run, you can still use Winamp 5.66 in Windows 11. Is it perfect? No. Will it do? Yes, simply because I enjoy this setup.
Below is a screenshot from a TV as a second monitor.
(Here is all my old Winamp stuff: https://www.tweakhound.com/files/winamp_stuff.zip)
Winamp 5.66 in Windows XP compatibility mode:


Still bada$$ after all these years