Free and open source software Initial release 21 October 2008 (2008-10-21) Latest stable release 2.2.1 (Froyo) / 23 September 2010; 43 days ago (2010-09-23) [2] Supported platforms ARM , MIPS , Power Architecture , x86 Kernel type Monolithic (modified Linux kernel ) Default user interface Graphical License Apache 2.0 and GNU General Public