File & Archive Management

muCommander [My Pick!] for Mac OS
muCommander is a lightweight, cross-platform file manager featuring a Norton Commander style interface and running on any operating system with Java support (Mac OS X, Windows, Linux, *BSD, Solaris...).
http://www.mucommander.com/

PeaZip [My Pick!] for Linux, Windows
PeaZip is an open source (LGPL), cross platform, portable archiver, supporting many archive formats: 7Z, BZ2, GZ, QUAD, PAQ, PEA, TAR, ZIP; reads ACE, ARJ, CAB, DEB, ISO, LHA, RAR, RPM etc...
http://peazip.sourceforge.net
我还有什么好说的？让所有收费的压缩软件都去死吧！

Springy [My Pick!]
Introducing Springy, simple and elegant, yet powerful archiving utility that will make your everyday archiving activities much more pleasurable.
http://www.springyarchiver.com

StuffIt Expander [My Pick!] for Mac OS
Completely redesigned for better performance, STUFFIT EXPANDER expands all your compressed and encoded files!
http://www.stuffit.com/mac/expander/