They were never going to remove that as this is all about only them benefiting from free dev resources.

I feel like programmers didn't care as much back in the days of Winamp. Doing plugins, skins and stuff. But the sentiment have changed. The age of freeware, nagware (Winrar) and shareware is gone.

It is all spyware or FOSS nowadays ...

I would have liked a Winamp port to Linux for nostalgias sake. But, dunno why anyone would bother with it now when you'd need to be sneaky about it or don't share it openly.

Audacious supports classic Winamp skins so if you're only after the aesthetics just use that. Alternatively you may be able to run the original Winamp through Wine.

I wonder, would publishing a diff be against the license?

I don't believe so, they can't control what you create or what others may do with it for personal use. They may only control winamp/their interests

The assumptions being, users of the patch get their own source and this isn't for commercial purposes. This is The Old Way

I think this is how we got MP3 support at large before the patents expired or something. Memory is failing me.

XMMS2!

I used to do plug-ins because it scratched an itch to code & provide things that'd be of use to others which when you've got a job to pay for that free time then it's less of an issue. Also the time of winamp & the plug-in / skin community of the time were somewhat reflective of how interested people were in tech vs how commoditised it's now become & generically boring imho. And I'm probably guilty of the change in behaviours with how I'm trying to fund wacup but 2 decades on is a long time & most of those early creatives have bills to pay.