用于反编译类文件和JAR的免费和/或开源选项有哪些？

I'm familiar with JAD, and haven't found anything newer or better, but I really didn't look that hard because I had previous experience with the JAD tool. However, I might have missed some really good options out there. Did I miss anything good? If so, what is it and what features does it have in comparison to JAD?, and haven't found anythi