After reading some more, I learned that he co-authored the spec for RSS (what you use to receive newsfeed on your mobile phone or Google Reader) when he was just 14.
And also on what might be the reason that got him down this way.
There was this piece from Tim Berners-Lee (well, the guy that created the World Wide Web)
"Aaron is dead.
Wanderers in this crazy world,
we have lost a mentor, a wise elder.
Hackers for right, we are one down,
we have lost one of our own.
Nurturers, carers, listeners, feeders,
we have lost a child.
Let us all weep.
and this screenshot from HackerNew
It's just simply sad.