I owe my entire career to the fact that Winamp added the ability to re-skin.

I had just graduated graduate school for international economics, and was working for a government contractor who only hired me because I had a masters (they could charge the government more). Because of this, I literally had nothing to do and would just sit in the office.

I eventually figured out an excuse to get my employer to buy Photoshop for me and I started learning it on company time. When Winamp came out with the update to add skins, I ended up making one of the very first skins (meshAMP) which became really popularly.

https://archive.org/details/winampskins_meshAmp

(I am cringing looking at it now)

This led to contract job with STB (to design interfaces for a TV Tuner card they had) and eventually 3DFX (paid in 3d video cards), and eventually a career change and a job as a graphic designer.

Except, I was not a good designer, so I quickly learned to program (ASP.net and then JAVA), which led to Macromedia Flash, which led to Macromedia Generator, which eventually led to a job offer from Macromedia (now Adobe), where I still am (sadly, sans Flash).

Anyways, thank your WinAMP!

Dockable UI, fast, stable, form and function. Really a masterclass in software design to this day.

I think those of us who use the REAPER DAW and its customizable themes are the main beneficiaries of that functionality.

You can reskin a lot of modern software, it just went out of fashion.

That's one of the biggest reasons I still use it. Other music players have strictly fixed UIs that often focus on organizing a music library rather than actually playing your music. I'm quite happy organizing my music using the file system.

It was really cool.

Skinning was pretty easy to do. The packaging format was a zip archive with a renamed extension. You could do a lot with a little photoshop skills and trial and error.

So many people used it that skins would get a lot of distribution, too.