Synapse was born.

With a classmate, Adam D’Angelo (now a student at CalTech and still a close friend) Zuckerberg designed a program that learned a listener’s musical tastes, and then designed a playlist to match.

“It learned your listening patterns by figuring out how much you like each song at a given point and time, and which songs you tend to listen to around each other,” Zuckerberg says.

The friends created a plug-in for the popular MP3 player WinAmp and posted it up for free on the Internet.

Today, Zuckerberg is reluctant to bring up the issue.

“At this point it’s so old that it’s not even worth discussing that much,” he says, trying to change the subject. But the fallout from Synapse was Zuckerberg’s first entry into the world of the “killer app.”

After the tech site Slashdot.org linked to the students’ site, the offers came rolling in. America Online, WinAmp and Microsoft—among others—all expressed interest in buying the program.

“Some companies offered us right off the bat up to one million, and then we got another offer that was like two million,” he says.

He and D’Angelo at first decided not to sell.

“I don’t really like putting a price-tag on the stuff I do. That’s just like not the point,” Zuckerberg says.

But after the two had matriculated to college, they decided to accept an offer—only to find the company was no longer interested.

“We were pretty naïve about it,” Zuckerberg admits. Today, he retains a legal counsel for his products.

Synapse may not have made Zuckerberg money, but it put him on the programming map. It also prepared him for the hype and corporate offers he would be faced with two years later, after thefacebook.com began its exponential growth across the country.

The site has been mentioned in The New York Times, CNN and other major news outlets.

Zuckerberg participated in a live television interview for CNBC, and says he has been wined and dined in Harvard Square by representatives from major software companies.