4.0.0 androidx.annotation annotation 1.0.0 Android Support Library Annotations The Support Library is a static library that you can add to your Android application in order to use APIs that are either not available for older platform versions or utility APIs that aren't a part of the framework APIs. http://developer.android.com/tools/extras/support-library.html 2013 The Apache Software License, Version 2.0 http://www.apache.org/licenses/LICENSE-2.0.txt repo The Android Open Source Project scm:git:https://android.googlesource.com/platform/frameworks/support http://source.android.com