Y Combinator started a video series named “How to Build the Future”. Mark Zuckerberg is interviewed in one of the videos.
There is one particularly interesting point in his interview, at 2:06. While talking about one of his more popular early projects, Course Match, he says
“And there were probably 10 other things like that that I built when I was at Harvard before I actually got around to building the first version of Facebook, that kind of added a lot of these things together.”
At a different point in the interview, he mentions that he started Facebook when he was 19, or in his sophomore year.
That means that he launched 10 different products in less than 2 years, while attending Harvard.