Android

Android is a software stack for mobile devices that includes an operating system, middleware and key applications. The Android SDK provides the tools and APIs necessary to begin developing applications that run on Android-powered devices.It was initially developed by Google and later the Open Handset Alliance.It allows developers to write managed code in the Java language, controlling the device via Google-developed Java libraries
 Features

    * 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

Google applications

Google has also participated in the Android Market by offering several applications for its services. These applications include Google Voice for the Google Voice service, Scoreboard for following sports, Sky Map for watching stars, Finance for their finance service, Maps Editor for their MyMaps service, Places Directory for their Local Search, Secrets for safely storing passwords and My Tracks, a jogging application. Android phones that include the 'Google Experience' also have Google Search, Google Calendar, Google Maps and Gmail integrated.

For more detail visit http://www.android.com/