software to run on the Android operating system. For non-recommendation questions, please ask on android.stackexchange.com, or stackoverflow.com for programming Android applications.
Android is an operating system for smart phones and other mobile devices. Primarily developed and distributed by Google, Android is an open source operating system based on a modified version of the Linux kernel.
Operating system for mobile devices. Developed by Google and the Open Handset Alliance.
Android page on Wikipedia
Detailed information about the Android OS.
General information about the Android OS.
Google I/O developer conference
Contains detailed videos and slides by Android product engineers