Open source and free archive utility program that was develop to compete with other file formats 7Zip sports the 7Z format which is an efficient compression format that competes head to head with Zip and RAR.
The current version of 7Zip supports many of other formats of file including the Zip and the RAR (only read).
Besides the archiver has own format - 7z which use allows to raise degree of compression of files considerably. Thus quality of archive can even exceed results with which archivers WinZip and WinRAR are capable to provide. The archiver 7-zip can be rather useful during those moments when it is necessary to pack files of the big size.
With respect to the archive utilities like WinZip and WinRAR, 7Zip is the completely free and open source which makes it the archive utility of the choice to many.
Also you may check out jZip – a free WinZip alternative