7-Zip is a free, open source software used to compress and uncompress files. The picture is an example of what 7-Zip looks like when running.
Packing and unpacking: 7z, XZ, BZIP2, GZIP, TAR, ZIP, and WIM
Unpacking only: ARJ, CAB, CHM, CPIO, CramFS, DEB, DMG, FAT, HFS, ISO, LZH, LZMA, MBR, MSI, NSIS, NTFS, RAR, RPM, SquashFS, UDF, VHD, WIM, XAR, and Z.
Also see: Compression Utility