Android, we said is an open source mobile software environment. It's built on top of Linux kernel.
Android is released under two different open source licenses:
|1.||GNU General Public License(GPL)||This is because Linux kernel this license is a requrement for anyone licensing the Linux kernel like android does.|
|2.||Apache Software License(ASL)||This excludes the kernel.|
Both licenses encourage the open source spirit.
However Apache license is friendlier towards commercialization. It endeavors to balance the "opensourceness" with commerical market forces.