Android 2.2 SDK (aka. Froyo)

http://developer.android.com/sdk/android-2.2.html
http://android-developers.blogspot.com/2010/05/android-22-and-developers-goodies.html

As google announce Android 2.2 in Google I/O, on the same time, the SDK is available for download.

Froyo focus following improvement:
1. Speed
2. APIs and Services
3. Browser
4. Android Market

Installing SDK Components

Important: Before you install SDK components, we recommend that you disable any antivirus programs that may be running on your computer.

Follow these steps to install new SDK components in your environment:

1.Launch the Android SDK and AVD Manager as described in the section above.
2.Select Available Packages in the left panel. This will reveal all of the components that are currently available for download from the SDK repository.
3. Select the component(s) you'd like to install and click Install Selected. If you aren't sure which packages to select, read Which components do I need?.
4. Verify and accept the components you want and click Install Accepted. The components will now be installed into your existing Android SDK directories.

New platforms are automatically saved into the /platforms/ directory of your SDK; new add-ons are saved in the /add-ons/ directory; samples are saved in the /samples/android-/; and new documentation is saved in the existing /docs/ directory (old docs are replaced).