Justin Frankel has brought music to desktops in numerous ways. After dropping out of college in 1997 and returning home to Arizona, he wrote Winamp, a program that let people play downloaded MP3 music files on their PCs. It was much easier to use than existing MP3 players. He and partner Tom Pepper also devised Shoutcast, which enables computers to broadcast like radio stations over the Internet. To vastly expand music’s availability online, Frankel then created Gnutella, a system that lets Internet users swap MP3s and other files. Unlike Napster, Gnutella does not pass files through a central distribution point—and recording companies can’t track them. By the time Frankel released Gnutella in 2000, he had sold Nullsoft, the company under which he developed Winamp and Gnutella, to America Online.AOL paid $400 million for Winamp and online-radio pioneer Spinner Networks and merged them under AOL Music in San Francisco. But AOL became wary of Gnutella because it let people acquire music they hadn’t paid for and pulled the program. What’s next from Frankel? “Just stuff that hopefully will make a difference,” the rebel says. That’s a tune he’s played before.