Additionally to Winamp, I guess what I will always remember Nullsoft with is also "NSIS - Nullsoft Scriptable Install System" [0]. In a previous job I sat down, read the docs and wrote a Windows-Installer for our product using this thing, since management didn't want to pay for InstallShield. What made quite an impression on me back then was the fact that the scripting language somewhat resembles assembly. [1] Also,…
https://github.com/robertsdotpm/win-auto-py3 (example exe points to resources on an old server i no longer have. so won't run but all the files and code are there and work.)
I wrote this when vibe coding wasn't a thing, could be a cool idea though to add mirror support for some resources the installer downloads and fallback to archive.org if hosts are down. That's one of the very cool things about NSIS -- everything you need for it already exists. Downloader, authentication, compression, all kinds of neat stuff. There's some many plugins for NSIS you could build working software just out of NSIS alone.