GZ is the file extension for gzip compressed files. Gzip stands for GNU zip, which is a free compression method based on the Deflate algorithm. GZ files should not be confused with zip archives. Gzip is part of almost every standard installation of Linux systems, but has no meaning on Windows and Mac OSX.
Gzip archives can in principle contain only a single file, but this can be circumvented by first combining the files with tar into a tarball and then packing them with gzip. These are usually recognized by the double ending .Tar.Gz or simply .Tgz.
GZ archives can be unpacked by just about any packer, be it Linux, Windows or Mac. This also applies to tgz files.
Most often resolving problems with opening GZ files is very simple. Just install an appropriate program that supports such files. All of the listed programs support GZ files, but may vary in offered function and purpose. Some programs may be capable only of viewing contents of GZ files or offer file conversion options, but may not be capable of editing such files.
It is possible that although a compatible program has been installed on user’s system, it is not used by the system to open it. This may happen because no default application was associated with this type of files. To associate GZ files with given application, select "Open with" from drop-down menu (accessed by right-clicking on the file). Then select from the list the program or application you want to be used to open this type of file. If the iArchiver applications is not on the list, select "Browse" option in order to manually locate the directory where iArchiver has been installed.
Sometimes problems with opening GZ files may not lie with the application itself, but can arise due to other causes, such as: