London’s hacking community descended on the Barbican Centre last weekend for 24 hours of music-app speed-coding, marking the third London Music Hack Day in three years.

What a difference a month makes. Back in November, during Boston’s Music Hack Day, Spotify was nowhere to be seen — only two hacks out of 56 took advantage of the music streaming service’s API. Since then, the company has thrown its doors wide open to developers. It announced an application platform on Nov. 30, complete with a selection of apps to start off with.

The result of that move? Sixteen of the 61 apps, more than one in...

Are you a loner? Don’t get along with others? Do you shout when you should be listening? Or stand off in a corner when you should be friendly? You may think nobody is noticing your anti-social behavior. You may even be right — for the moment.

But Darpa, the Pentagon’s way-out research arm, is looking for a way to track your abnormal activities. It will do this with voice-sensing technology and algorithms that decode your body language. And then, it will correct your actions.

A new Pentagon experiment called “Assessment of Asymmetric Social Indicators” is setting out to build a sensor that picks ...