The Android NDK provides tools that allow Android application developers to embed components that make use of native code in their Android applications.
The Android NDK is a companion tool to the Android SDK that lets Android application developers build portions of their apps in native code. It is designed for use only in conjunction with the Android SDK, so if you have not already installed the Android 1.5 SDK, please do so before downloading the NDK.
The Native Development Kit comes with a series of cross-toolchains (compilers, linkers, etc..) that you can use to create native ARM binaries.
It provides a set of system headers for stable native APIs that are guaranteed to be supported in all later releases of the platform:
· libc (C library) headers
· libm (math library) headers
· JNI interface headers
· libz (Zlib compression) headers
· liblog (Android logging) header
· A Minimal set of headers for C++ support
The NDK also provides a build system that lets you work efficiently with your sources, without having to handle the toolchain/platform/CPU/ABI details. You create very short build files to describe which sources to compile and which Android application will use them — the build system compiles the sources and places the shared libraries directly in your application project.

· A set of tools and build files used to generate native code libraries from C and C++ sources
· A way to embed the corresponding native libraries into application package files (.apks) that can be deployed on Android devices
· A set of native system headers and libraries that will be supported in all future versions of the Android platform, starting from Android 1.5
· Documentation, samples, and tutorials

Requirements:
· A complete Android SDK installation (including all dependencies) is required.
· Android 1.5 SDK or later version is required.
· GNU Make 3.81 or later is required. Earlier versions of GNU Make might work but have not been tested
· Cygwin
· The native libraries created by the Android NDK can only be used on devices running the Android 1.5 platform version or later. This is due to toolchain and ABI related changes that make the native libraries incompatible with 1.0 and 1.1 system images.
· For this reason, you should use native libraries produced with the NDK in applications that are deployable to devices running the Android 1.5 platform version or later. To ensure compatibility, an application using a native library produced with the NDK m

What's New in This Release:
Addresses the following problems in the r5 release:
· The r5 binaries required glibc 2.11, but the r5b binaries are generated with a special toolchain that targets glibc 2.7 or higher instead. The Linux toolchain binaries now run on Ubuntu 8.04 or higher.
· Fixes a compiler bug in the arm-linux-androideabi-4.4.3 toolchain. The previous binary generated invalid thumb instruction sequences when dealing with signed chars.
· Adds missing documentation for the "gnustl_static" value for APP_STL, that allows you to link against a static library version of GNU libstdc++.
The following ndk-build issues are fixed:
· A bug that created inconsistent dependency files when a compilation error occured on Windows. This prevented a proper build after the error was fixed in the source code.
· A Cygwin-specific bug where using very short paths for the Android NDK installation or the project path led to the generation of invalid dependency files. This made incremental builds impossible.
· A typo that ...