ProGuard is our free Java class file optimizer and obfuscator. It detects and removes unused classes, fields, methods, and attributes. It optimizes bytecode and removes unused instructions. It renames the remaining classes, fields, and methods using short meaningless names. ProGuard is mainly popular in the development of Android apps, JME midlets, and large commercial Java applications and libraries.
Version 4.8 mostly fixes a series of minor problems in configuration parsing, optimization, and obfuscation. It also adds string optimizations to the optimization step, and small enhancements for configuration with the Ant task. This version is entirely compatible with previous versions, so upgrading is simply a matter of switching to the new jars.
Android developers may also be interested in the release of ProGuard's new specialized sibling for Android, DexGuard -- see our other announcement.
Regards,Eric Lafortune -- developer of ProGuard and DexGuard