The Android platform is a software stack for mobile devices including an operating system, middleware and key applications. Developers can create applications for the platform using the Android SDK. Applications are written using the Java programming language and run on Dalvik, a custom virtual machine designed for embedded use, which runs on top of a Linux kernel.
If you want to know how to develop applications for Android, you're in the right place. This site provides a variety of documentation that will help you learn about Android and develop mobile applications for the platform.

· Application framework enabling reuse and replacement of components
· Dalvik virtual machine optimized for mobile devices
· Integrated browser based on the open source WebKit engine
· Optimized graphics powered by a custom 2D graphics library; 3D graphics based on the OpenGL ES 1.0 specification (hardware acceleration optional)
· SQLite for structured data storage
· Media support for common audio, video, and still image formats (MPEG4, H.264, MP3, AAC, AMR, JPG, PNG, GIF)
· GSM Telephony (hardware dependent)
· Bluetooth, EDGE, 3G, and WiFi (hardware dependent)
· Camera, GPS, compass, and accelerometer (hardware dependent)
· Rich development environment including a device emulator, tools for debugging, memory and performance profiling, and a plugin for the Eclipse IDE

Requirements:
· Eclipse IDE
· JDK 5 or JDK 6 (JRE alone is not sufficient)
· Android Development Tools plugin (optional, but recommended)
· Not compatible with Gnu Compiler for Java (gcj)
· For the base SDK package, at least 600MB of available disk space. For each platform downloaded into the SDK, an additional 100MB is needed.

What's New in This Release:
Dependencies:
· If you are developing in Eclipse with ADT, note that the SDK Tools r9 is designed for use with ADT 9.0.0 and later. After installing SDK Tools r9, we highly recommend updating your ADT Plugin to 9.0.0.
· If you are developing outside Eclipse, you must have Apache Ant 1.8 or later.
Upgrading to SDK Tools r9:
· If you are upgrading to SDK Tools r9 from SDK Tools r7 or earlier, the default installed location for the adb tool has changed from /tools/adb to /platform-tools/adb. This means that you should add the new location to your PATH and modify any custom build scripts to reference the new location. Copying the adb executable from the new location to the old is not recommended, since subsequent updates to the SDK Tools will delete the file.
General notes:
· The default ProGuard configuration, proguard.cfg, now ignores the following classes
· classes that extend Preference
· classes that extend BackupAgentHelper
· Ant lib rules now allow you to override java.enco...