Android SDK m5-rc14 now available. There are a couple of changes in m5-rc14 which can be highlight:ed

    * New user interface - As mentioned once it was introduced the m3 version of the Android SDK, we’re continuing to refine the UI that’s available for Android. m5-rc14 replaces the previous placeholder with a new UI, but as before, work on it is still in-progress.
    * Layout animations - Developers can now create layout animations for their applications using the capabilities introduced in the android.view.animation package. Check out the LayoutAnimation*.java files in the APIDemos sample code for examples of how this works.
    * Geo-coding - android.location.Geocoder enables developers to forward and reverse geo-code (i.e. translate an address into a coordinate and vice-versa), and also search for businesses.
    * New media codecs - The MediaPlayer class has added support for the OGG Vorbis, MIDI, XMF, iMelody, RTTL/RTX, and OTA audio file formats.
    * Updated Eclipse plug-in - A new version of ADT is available and provides improvements to the Android developer experience. In particular, check out the new Android Manifest editor.

You can find more information about what’s changed in a couple of documents that have been published. First is an overview of the changes to the Android APIs in API Changes Overview. If you want a more granular view of what’s changed, an API diff between m3-rc37 and m5-rc14 is also available. Finally, Upgrading the SDK provides links to the two previously referenced documents and the release notes, as well as instructions on how to upgrade your development environment.

We still need your help in shaping the platform, so if you find issues with the Android APIs or the developer tools, please let us know through the Android Issue Tracker. If you have general comments or questions, please head on over to the Android groups to get in touch.

We’re looking forward to all the applications that developers will create using this new version of the Android SDK. Of course, you can use m5-rc14 or any older version of the SDK for your Android Developers Challenge submission.

Jason Chen, Developer Advocate
Google Android

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.

What is Android?

Android is a software stack for mobile devices that includes an operating system, middleware and key applications. This early look at the Android SDK provides the tools and APIs necessary to begin developing applications on the Android platform using the Java programming language.

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

Applications

Android will ship with a set of core applications including an email client, SMS program, calendar, maps, browser, contacts, and others. All applications are written using the Java programming language.
Application Framework

Developers have full access to the same framework APIs used by the core applications. The application architecture is designed to simplify the reuse of components; any application can publish its capabilities and any other application may then make use of those capabilities (subject to security constraints enforced by the framework). This same mechanism allows components to be replaced by the user.

Underlying all applications is a set of services and systems, including:

    * A rich and extensible set of Views that can be used to build an application, including lists, grids, text boxes, buttons, and even an embeddable web browser
    * Content Providers that enable applications to access data from other applications (such as Contacts), or to share their own data
    * A Resource Manager, providing access to non-code resources such as localized strings, graphics, and layout files
    * A Notification Manager that enables all applications to display custom alerts in the status bar
    * An Activity Manager that manages the life cycle of applications and provides a common navigation backstack

Libraries

Android includes a set of C/C++ libraries used by various components of the Android system. These capabilities are exposed to developers through the Android application framework. Some of the core libraries are listed below:

    * System C library - a BSD-derived implementation of the standard C system library (libc), tuned for embedded Linux-based devices
    * Media Libraries - based on PacketVideo’s OpenCORE; the libraries support playback and recording of many popular audio and video formats, as well as static image files, including MPEG4, H.264, MP3, AAC, AMR, JPG, and PNG
    * Surface Manager - manages access to the display subsystem and seamlessly composites 2D and 3D graphic layers from multiple applications
    * LibWebCore - a modern web browser engine which powers both the Android browser and an embeddable web view
    * SGL - the underlying 2D graphics engine
    * 3D libraries - an implementation based on OpenGL ES 1.0 APIs; the libraries use either hardware 3D acceleration (where available) or the included, highly optimized 3D software rasterizer
    * FreeType - bitmap and vector font rendering
    * SQLite - a powerful and lightweight relational database engine available to all applications

Android Runtime

Android includes a set of core libraries that provides most of the functionality available in the core libraries of the Java programming language.

Every Android application runs in its own process, with its own instance of the Dalvik virtual machine. Dalvik has been written so that a device can run multiple VMs efficiently. The Dalvik VM executes files in the Dalvik Executable (.dex) format which is optimized for minimal memory footprint. The VM is register-based, and runs classes compiled by a Java language compiler that have been transformed into the .dex format by the included "dx" tool.

The Dalvik VM relies on the Linux kernel for underlying functionality such as threading and low-level memory management.

Linux Kernel

Android relies on Linux version 2.6 for core system services such as security, memory management, process management, network stack, and driver model. The kernel also acts as an abstraction layer between the hardware and the rest of the software stack.

Download the latest  SDK from here