CFR is a Java decompiler that can decompile modern Java features up to Java 14, written entirely in Java 6, making it compatible across different Java versions. It can also decompile class files from other JVM languages back into Java. To use, run the specific version jar with the class name(s) you want to decompile or provide a jar path to decompile the entire jar and add --outputdir /tmp/putithere to emit files.