The purpose of mhealthx is to create a uniform framework to extract features from a variety of different sensor data sources, particularly suited to mobile health research, and to promote open science by making all software and documentation freely and openly available.
We have chosen the Apache v2.0 license because it is liberal and supports broad use and modification of the software. The Apache license allows other projects with virtually any license, including GPL, to use our code, and makes it more likely that we will attract support from companies, including open-source software companies, such as Continuum Analytics, Enthought, and Kitware.