If you use Windows you must be aware of Winzip utility.Winzip is not free and after evaluation version it forces you to wait for sometime before you may use it. Also, Winzip doesn’t support all type of encrypted files zipped on Unix platform. There are cases where one have to Unzip files on Windows compressed on Unix system.Unix system typically uses tar,bzip2,gzip,tgz format to zip files.
7-zip is free open source alternative which supports files even compressed on Unix system.7-zip provides command line interface as well as GUI based File manager.7-zip supports packing/unpacking of 7z,zip,gzip,bzip2 and tar files.7-zip also support unpacking only of arj,cam,chm,cpio,deb,dmg,hfs,iso,lzh,lzma,msi,nsis,rar,rpm,udf,wim,xar and z files.
I am using 7-zip and I am very happy with this.Please share your experience.You may download 7-zip from http://www.7-zip.org/ website.