It's easy for Windows users to forget that WinZip isn't the only file-compression utility in the world, nor is WinRAR its only replacement. Like its better-known competitors, the free 7-Zip unpacks a host of archive formats, including ZIP, TAR, GZ, and its own 7Z format. Unlike the competition, though, it can create TAR and GZ archives, which are commonly used on Unix and Linux systems. Even though it's small, there's an even smaller portable version, too.
The program's ability to shrink files was stunning. 7Z archives tested up to 40 percent smaller then their ZIP equivalents, although compression did take longer, and the highest compression settings can hog system resources. Advanced options include the ability to create solid and self-extracting archives, and to adjust the compression level and password protection. The program also has a command line module. Though the main interface is overly simple and looks like it was designed for Windows 95, it's not hard to use and just about as self-explanatory as a program can get. The context menu options, which include "testing" an archive, indicate that 7-Zip should be taken seriously.