MP3.com

3) MP3.com

MP3 set music free.

The audio format compresses digital music so fans can easily store thousands of songs on tiny players and transfer them via the Web. Thank the Moving Pictures Experts Group (MPEG) for creating the MP3, but it was MP3.com and founder Michael Robertson (at left), who helped make it popular.

In the late 1990s, companies such as Microsoft, RealNetworks, and even AT&T were working on audio formats protected by DRM, which would limit sharing but also make it hard for people to move their songs between their own different devices. Robertson recognized that the public would never accept this. MP3 is now the de facto download format.

Robertson is also the godfather of cloud music. A decade ago, MP3.com began scanning users' computer hard drives and then offered to stream the same songs to any of their Web-enabled devices. Enabling this kind of ubiquitous access is what Google and Amazon have begun doing recently and what Apple is expected to do soon. Later, MP3.com went public, was sued by the record labels and then sold. A watered-down version ended up at CNET.

"Without Robertson, Napster would have never happened," said Wayne Rosso, former president of Grokster. "People in the music industry would s--- on him all the time, but he was a decade ahead of the curve. He is digital music's Ho Chi Minh."