1**ProGuard** is distributed under the terms of the GNU General Public License. 2Please consult the [license page](license.md) for more details. 3 4ProGuard is written in Java, so it requires a Java Runtime Environment 5(JRE 1.8 or higher). 6 7You can download ProGuard in various forms: 8 9- [Pre-built artifacts](https://bintray.com/guardsquare/proguard) at JCenter 10- [Pre-built artifacts](https://search.maven.org/search?q=g:com.guardsquare) at Maven Central 11- [Traditional pre-built archives](https://sourceforge.net/projects/proguard/files/) at SourceForge 12- A [Git repository of the source code](https://github.com/Guardsquare/proguard) at Github 13- The [complete ProGuard manual](https://www.guardsquare.com/proguard) at Guardsquare 14 15You can find major releases, minor releases with important bug fixes, and 16beta releases with the latest new features and any less urgent bug fixes. 17 18If you're still working with an older version of ProGuard, check out the 19[release notes](releasenotes.md), to see if you're missing something essential. 20Unless noted otherwise, ProGuard remains compatible across versions, so 21don't be afraid to update. 22