Dissecting the SDK of Android

Whenever I download an SDK, I like to take a look at the files I've installed. Often, there is a wealth of information hidden in the SDK itself that is not readily visible from the documentation. So here's what you'll find in the Android SDK on a Windows machine:

android.jar - The Android application framework. Unzipping this jar reveals the entire class structure and all of the supporting classes of the framework. Currently there is no source.

docs - 100 megabytes worth of documentation, samples, etc.

samples - Six different sample applications - ApiDemos, HelloActivity, LunarLander, NotePad, SkeletonApp and Snake

tools - the various SDK binaries such as aapt, acp, and emulator live here.

lib - various templates and supporting jar files live in this directory

activityCreator - the activityCreator python application lives here.

images - The Linux file system images are found in this directory: ramdis.img, system.img and userdata.img. They are YAFFS2 file system images, so I couldn't open them without additional kernel support on my Fedora system.

skins - supporting emulator graphics for HVGA and QVGA screens in both landscape and portrait format.