Android software development kit
The Android software development kit (SDK)
includes everything you need to start developing, testing, and debugging Android applications. Included in the SDK download are:
The Android APIs
The core of the SDK is the Android API libraries that provide developer access to the Android stack. These are the same libraries used at Google to create native Android applications.
To turn Android source code into executable Android applications, the SDK includes several development tools that let you compile and debug your applications
The Android Emulator
The Android Emulator is a fully interactive Android device emulator featuring several alternative skins. Using the emulator, you can see how your applications will look and behave on a real Android device. All Android applications run within the Dalvik VM so that the software emulator is an excellent environment, in fact, as it is hardware-neutral, it provides a better independent test environment than any single hardware implementation.
The SDK includes extensive code-level reference information detailing exactly whatís included in each package and class and how to use them. In addition to the code documentation, Androidís reference documentation explains how to get started and gives detailed explanations of the fundamentals behind Android development.
The Android SDK includes a selection of sample applications that demonstrate some of the possibilities available using Android, as well as simple programs that highlight how to use individual API features.
Despite its relative youth, Android has generated a vibrant developer community. The Google Groups at http://code.google.com/android/groups are active forums of Android developers with regular input from the Android development team at Google. For those using the popular Eclipse IDE, Android has released a special plug-in that simplifies project creation and tightly integrates Eclipse with the Android Emulator and debugging tools