The Android operating system displays both the advantages and challenges of open source software. Android is immensely popular, and is now the leading smartphone operating system, having recently surpassed Symbian and the Apple iOS. However, Android is a very complex product which uses over 19 licenses with different obligations.
Although Android is distributed under the Apache Software License, a number of components are licensed under the GNU General Public License version 2. In fact, Android is based on the Linux kernel which is licensed under a special version of the GPLv2, limiting the scope of the GPLv2 (and it is worth noting that Google’s compliance with GPLv2 for the Linux kernel was recently the source of controversy). The GPLv2 is the most widely used open source license and is “copyleft,” which means that derivative works must be licensed under GPLv2. In addition to the Linux kernel, some components of Android itself are also licensed under the GPLv2.
