Unix .TAR file archive compressed with Gnu Zip (.GZIP) compression; the TAR file archives multiple files into one file and the Gzip compression reduces the archive file size.
To decompress a TGZ file from a Unix command line:
First type "gunzip filename.tar.gz" and press Enter.
This decompresses the archive.
Then type "tar -xf packed_files.tar" and press Enter.
This decodes the TAR archive and makes the the files readable.
NOTE: TGZ files are commonly used as install packages for Slackware Linux.
Program(s) that open tgz files
Mac: Smith Micro StuffIt Deluxe for Mac; Zipeg Windows: Smith Micro StuffIt Deluxe for Windows; RARLAB WinRAR; Corel WinZip; Zipeg
Unix: tar; gunzip; pkgtool
Information from FileInfo.com - The File Extensions Resource.
http://www.fileinfo.com/extension/tgz