Zipper and 7-Zip are good unzip utilities that are available as freeware. Although both programs are free, the developers of the programs accept donations on PayPal.
As 7-Zip comes in two versions, users must download the correct one. Although the 32-bit version works on both 32-bit and 64-bit systems, the 64-bit version will only work on 64-bit operating systems. The 32-bit version may perform poorly on 64-bit systems and lacks some of the features available in the 64-bit version.
Beta versions of 7-Zip are also available on the website. A list of beta versions is located on the right side of the site at 7-Zip.org. Beta versions offer more features but are sometimes unstable.