(It is quite amusing to read the release notes: "SVG features (the equalizer display) requires Deer Park Alpha 1 or later (Deer Park is the codename for Firefox 1.1, to be released in September).")
This being 2005, the code is pretty much what you see there -- no minification or anything. The source archive contains the template files (this project was done as a skin for BrowseAmp, a plugin which added a web server to Winamp to allow remote control of it).
Anyone remember Phoenix 0.1.0? Phoenix became Firebird became Firefox.
I think it is fair to say that not forcing people to have a web authoring tool that reminds them they are the author contributed greatly to the new web of walled gardens.
It feels very wrong but after 20 years and 100 GB of pop3 email, it's hard to switch I suppose.