These are gzip-compressed tar archives. If you have the GNU tar utility (included in all GNU/Linux distributions and many other versions of Unix including Mac OS X (Darwin), and available for MS-Windows as part of the free Cygwin software development package), you can unpack foo.tar.gz in one step: tar xfvz foo.tar.gz If you have another version of tar, it may not support the z option, and you may need to decompress using gzip before unpacking, like this: gzip -d foo.tar.gz tar xfv foo.tar (If you don't have gzip, free versions are available for all popular operating systems from gzip.org.) If your browser decompressed the archive while downloading it, simply unpack it: tar xfv foo.tar The popular WinZip utility can unpack .tar and .tar.gz archives under MS Windows, but it does not recognize .tar.gz format unless the file names end in .tar.gz (as such files appear on this site). Your browser may rename such files when you download them, replacing the first ``.'' with ``_''.