There are two distributions of Proguard in the tree: * external/proguard, which is used by the platform * prebuilts/tools/common/proguard, which is used by the tools (and distributed to users in the tools/ folder) These are updated independently since one evolves with the platform, and the other with the tools. Even though there is a MODULE_LICENSE_GPL license marker in this directory, note that the Android SDK has an explicit exemption as described in the license.html file. The proguard4.7 directory contains the unzipped contents of the official Proguard 4.7 zip file, available from http://proguard.sourceforge.net/index.html The .zip file is also included here such that the source code can easily be used (when debugging) or the distribution rebuilt from source (if for some reason the above repository should be unavailable). The sdk/build/tools.atree script will copy part of the proguard4.7 tree into the tools/ directory. It skips the src/ directory (except for task.properties) and build/. Therefore, we removed the following two lines from the README file: - src : the source code - build : various alternative build scripts such that the copied README reflects the actual contents of the distributed tree. In addition, we added a paragraph to state that the distribution was slightly modified. In addition, the sdk/build/tools.atree will copy in the license.html file, which was obtained via wget http://proguard.sourceforge.net/license.html (and the JavaScript redirect element in the <head> was removed)