The Android Support Library is offered as an SDK extra component that can be installed from the Android SDK Manager and located at the path sdk\extras, say C:\adt-bundle-windows\sdk\extras. It contains static libraries providing access to newer APIs on older platforms and various helper classes.

Each library is called v<api>, indicating the minimum API level that they require.

To use those libraries:

• simply copy them as static libraries into your project or
• right-click on the project and choose from the context menu, Android Tools>Add Support Library

The following are excerpts from the library README.txt:

*** V4 ***

v4/android-support-v4.jar contains:
– Fragment API. New in API 11 (3.0 – Honeycomb). http://developer.android.com/reference/android/app/Fragment.html
– Loader API. New in API 11 (3.0 – Honeycomb). http://developer.android.com/reference/android/app/LoaderManager.html
– CursorAdapter / ResourceCursorAdapter / SimpleCursorAdapter. These are the API 11 versions.
– MenuCompat allows calling MenuItem.setShowAsAction which only exists on API 11.

v4/src/ is the source code for the compatibility library
v4/samples/ provides a sample app using the library.
*** V13 ***

v13/android-support-v13.jar provides the same features as v4, plus:
– FragmentPagerAdapter: Implementation of PagerAdapter that represents each page as a Fragment.

v13/src/ is the source code for the compatibility library, not including the v4 source
v13/samples/ provides a sample app using the library.

• References
  • Quoting and citing with <blockquote>, <q>, <cite>, and the cite attribute
  • HTML 5.1 – Editor’s Draft 11 December 2012