The module uses a new version of Intel's Quark chip, the Quark SE, to enable such compact wearable technologies. It's capable of being integrated into such small form factors that Brian Krzanich , CEO of the company,  even showed it off in a coat button on stage. Curie uses Bluetooth LE and includes a low-power sensor hub, a pattern-matching accelerator that allows for accurate gesture recognition, and a six-axis combination accelerometer and gyroscope, all crucial ingredients for making compact wearables. On top of all that Curie runs Viper, an open-source software that can take the information gathered by those internals and use it for things like activity recognition or step tracking.

More info at: Intel's Web Site.