You don't need a particularly powerful PC for selecting and playing music, but adding CDs and other maintenance tasks are a lot more pleasant with a fast PC. It doesn't have to be sited near the amplifier and speakers — anywhere within cable range will do, in a separate room if desired. In day-to-day operation there's no need to look at it or touch it.
The WiFi Access Point can be sited anywhere within cable range of the server PC. Signal quality is the important criterion when selecting a location.
There's not much to say about the Apache HTTP server software. After installation it needs a small amount of work to configure it, then it just sits there in the background quietly handing out pages in response to requests from the browser in the remote control.
An important element of server configuration is the "Document Root", which is a folder on the server PC hard disk. When the server receives a request from a browser, the "Document Root" is the directory that the server goes to for the requested page. The principal contents of the Document Root folder for the jukebox server are:
The Start Page, named "index.html", is requested when the remote control browser is started, or when the user clicks on the browser's Home button. The Start Page is a frameset, with the screen divided into four frames:

The four frames of the Start PageThat frameset stays in place permanently. The sources of the frame contents are as follows:
The CGI programs create HTML pages and send commands to Winamp on request, using information that can vary from time to time. The major sources of such variable information are:
Winamp is the program that plays the music and maintains the queue of music waiting to be played (in Winamp this is called the "playlist").
A Winamp plug-in called httpQ provides an HTTP server that allows other programs to control and monitor Winamp functions. The CGI programs player.cgi and queue.cgi communicate with Winamp using httpQ.
Winamp uses Windows Media Encoder to decompress the music files.