No matter the format of the compressed file, you'll be able to unpack more than 40 different formats, including CAB, ARJ, LZH, TAR, GZ, ACE, UUE, BZ2, JAR, ISO, RAR, Zip or 7Z, you'll only have to double-click its icon and the content of the file will appear on screen, then choose whether to unpack it or run the files without having to unpack it previously. Furthermore, Winrar offers a very good compression ratio above the average, what means the files you compress using it will be smaller than when compressed using other program. Finally, you can also protect files using Rinjdael (AES-128) encryption system, digital signature or protect it against modifications.
Winrar is probably the best compression tool out there. The high quantity of options, as well as its versatility and easiness of use make it a must have for any user.
40 days evaluation version. After that period a registry message will be shown, however, you will be able to use the program with no problem.