As you may have noticed, the source code for Android 2.2, which we call Froyo, has been released.
The Android 2.2 SDK that was released at Google I/O contained a preview of the Froyo system image and today, we are releasing an update to bring it into sync with the system image pushed to Nexus One devices.
I encourage all developers to use the SDK manager to update to this version.

Today at Google I/O we announced that Android 2.2 is right around the corner. This is our seventh platform release since we launched Android 1.0 in September 2008. We wanted to highlight five areas in particular:

Performance & speed: The new Dalvik JIT compiler in Android 2.2 delivers between a 2-5X performance improvement in CPU-bound code vs. Android 2.1 according to various benchmarks. New enterprise capabilities: We’ve added Exchange capabilities such as account auto-discovery and calendar sync. Device policy management APIs allow developers to write applications that can control security features of the device such as the remote wipe, minimum password, lockscreen timeout etc. Faster, more powerful browser: We have brought the V8 JavaScript engine to the Android browser as part of 2.2. This has resulted in a 2-3X improvement in JavaScript performance vs. 2.1. Rich set of new APIs and services: New data backup APIs enable apps to participate in data backup and restore, allowing an application's last data to be restored when installed on a new or a reset device. Apps can utilize Android Cloud to Device Messaging to enable mobile alert, send to phone, and two-way push sync functionality. Developers can now declare whether their app should be installed on internal memory or an SD card. They can also let the system automatically determine the install location. On the native side, a new API now gives access to Skia bitmaps. Additions to Android Market: Android Market provides Android Application Error Reports, a new bug reporting feature, giving developers access to crash and freeze reports from users. Developers will be able to access these reports via their account on the Android Market publisher website.

For a complete list of everything we’ve included in Android 2.2, please see the platform highlights.
Developers can now download the Android 2.2 SDK and Android NDK, Revision 4 from the Android developer site.
Tools update
We are releasing new version of the Android SDK Tools, Revision 6, Eclipse plug-in ADT 0.9.7 and Android NDK, Revision 4.

Android SDK Tools, Revision 6, Eclipse plug-in 0.9.7 These new versions include support for library projects that will help you share code and resources across several Android projects. Android NDK, Revision 4 Workflow improvements The new NDK brings a host of workflow improvement, from compilation, to debugging. Starting with 2.2, the NDK enables debugging native code on production devices. ARMv7 instruction set support This release enables the generation of machine code for the ARMv7-A instruction set. Benefits include higher performance, as well as full use of the hardware FPU for devices that support it. ARM Advanced SIMD (a.k.a. NEON) instruction support The NEON instruction set extension can be used to perform scalar computations on integers and floating points. However, it is an optional CPU feature and will not be supported by all Android ARMv7-A based devices. The NDK includes a tiny library named "cpufeatures" that can be used by native code to test at runtime the features supported by the device's target CPU.

For more information, please see the releases notes for the SDK Tools, ADT, and NDK.
Finish thanks ,

Today we're announcing a new version of the Android platform — Android 2.3 (Gingerbread). It includes many new platform technologies and APIs to help developers create great apps. Some of the highlights include:

Enhancements for game development: To improve overall responsiveness, we’ve added a new concurrent garbage collector and optimized the platform’s overall event handling. We’ve also given developers native access to more parts of the system by exposing a broad set of native APIs. From native code, applications can now access input and sensor events, EGL/OpenGL ES, OpenSL ES, and assets, as well a new framework for managing lifecycle and windows. For precise motion processing, developers can use several new sensor types, including gyroscope. Rich multimedia: To provide a great multimedia environment for games and other applications, we’ve added support for the new video formats VP8 and WebM, as well as support for AAC and AMR-wideband encoding. The platform also provides new audio effects such as reverb, equalization, headphone virtualization, and bass boost. New forms of communication: The platform now includes support for front-facing camera, SIP/VOIP, and Near Field Communications (NFC), to let developers include new capabilities in their applications.

For a complete overview of what’s new in the platform, see the Android 2.3 Platform Highlights.
Alongside the new platform, we are releasing updates to the SDK Tools (r8), NDK, and ADT Plugin for Eclipse (8.0.0). New features include:

Simplified debug builds: Developers can easily generate debug packages without having to manually configure the application’s manifest, making workflow more efficient. Integrated ProGuard support: ProGuard is now packaged with the SDK Tools. Developers can now obfuscate their code as an integrated part of a release build. HierarchyViewer improvements: The HierarchyViewer tool includes an updated UI and is now accessible directly from the ADT Plugin. Preview of new UI Builder: An early release of a new visual layout editor lets developers create layouts in ADT by dragging and dropping UI elements from contextual menus. It’s a work in progress and we intend to iterate quickly on it.

To get started developing or testing applications on Android 2.3, visit the Android Developers site for information about the Android 2.3 platform, the SDK Tools, the ADT Plugin and the new NDK.

Android 3.0 (Honeycomb) is a new version of the Android platform that is designed from the ground up for devices with larger screen sizes, particularly tablets. It introduces a new “holographic” UI theme and an interaction model that builds on the things people love about Android — multitasking, notifications, widgets, and others — and adds many new features as well.
Besides the user-facing features it offers, Android 3.0 is also specifically designed to give developers the tools and capabilities they need to create great applications for tablets and similar devices, together with the flexibility to adapt existing apps to the new UI while maintaining compatibility with earlier platform versions and other form-factors.
Today, we are releasing a preview of the Android 3.0 SDK, with non-final APIs and system image, to allow developers to start testing their existing applications on the tablet form-factor and begin getting familiar with the new UI patterns, APIs, and capabilties that will be available in Android 3.0.
Here are some of the highlights:

UI framework for creating great apps for larger screen devices: Developers can use a new UI components, new themes, richer widgets and notifications, drag and drop, and other new features to create rich and engaging apps for users on larger screen devices. High-performance 2D and 3D graphics: A new property-based animation framework lets developers add great visual effects to their apps. A built-in GL renderer lets developers request hardware-acceleration of common 2D rendering operations in their apps, across the entire app or only in specific activities or views. For adding rich 3D scenes, developers take advantage of a new 3D graphics engine called Renderscript. Support for multicore processor architectures: Android 3.0 is optimized to run on either single- or dual-core processors, so that applications run with the best possible performance. Rich multimedia: New multimedia features such as HTTP Live streaming support, a pluggable DRM framework, and easy media file transfer through MTP/PTP, give developers new ways to bring rich content to users. New types of connectivity: New APIs for Bluetooth A2DP and HSP let applications offer audio streaming and headset control. Support for Bluetooth insecure socket connection lets applications connect to simple devices that may not have a user interface. Enhancements for enterprise: New administrative policies, such as for encrypted storage and password expiration, help enterprise administrators manage devices more effectively.

For an complete overview of the new user and developer features, see the Android 3.0 Platform Highlights.
Additionally, we are releasing updates to our SDK Tools (r9), NDK (r5b), and ADT Plugin for Eclipse (9.0.0). Key features include:

• UI Builder improvements in the ADT Plugin:
  • Improved drag-and-drop in the editor, with better support for included layouts.
  • In-editor preview of objects animated with the new animation framework.
  • Visualization of UI based on any version of the platform. independent of project target. Improved rendering, with better support for custom views.

To find out how to get started developing or testing applications using the Android 3.0 Preview SDK, see the Preview SDK Introduction. Details about the changes in the latest versions of the tools are available on the SDK Tools, the ADT Plugin, and NDK pages on the site.
Note that applications developed with the Android 3.0 Platform Preview cannot be published on Android Market. We’ll be releasing a final SDK in the weeks ahead that you can use to build and publish applications for Android 3.0.