A PET file is an application installation package file created and used with PuppyLinux variant of Linux Operating System. It is created as a compressed TGZ file that reduces the file size of the compressed archive. The integrity of PET file format is ensured by the md5sum checksum that is appended to the end of the file for verification at the remote end. PET files can be extracted using the standard TGZ file extractor and WinRAR. PET files replaced the old PUP package installation files.
PET File Format
PET files are saved to disc as compressed archives in binary file format. However, the internal file format details of PET file format is not known. Similar to .exe and .msi package installation files, the PET files start an installation when they are executed.