Earlier quoted context omitted.
And Limewire. I remember using Limewire to pirate Limewire Pro
On Windows, Audiogalaxy. And on Mac, Poisoned! With support for FastTrack (Kazaa), Gnutella (Limewire), OpenFT, OpenNap, and eMule. But dial-up was too slow, so it was usually quicker to repair a friend's iPod and make a backup using iPodRip or Senuti.
It soon became very clear the problems of centralization for this purpose, decentralized networks thrived. Most proprietary implementation eventually died. The open ones, emule and gnutella2, although a small shadow of what they were, are still alive.
In the meantime bittorrent evolved and the industry had to bow to streaming services.
But, if anyone still wants to "fell the napster taste", the closest I know today is soulseek. There's a good client, called nicotine+, that works very well last time I tried.