Android is an open-source software stack created for mobile phones and other devices. The Android Open Source Project (AOSP), led by Google, is tasked with the maintenance and further development of Android. Many device manufacturers have brought to market devices running Android, and they are readibly available around the world.
Our primary purpose is to build an excellent software platform for everyday users. A number of companies have committed many engineers to achieve this goal, and the result is a full production quality consumer product whose source is open for customization and porting.
You can find more information about Android from these pages: