: The official, free tool for Windows is available at 7-Zip.org .
: If the "sum" part of the name refers to a checksum (like MD5 or SHA-256), the archive may contain a manifest used to verify that other files have not been corrupted. greetsum.7z
: Once installed, right-click the greetsum.7z file. : The official, free tool for Windows is available at 7-Zip
: Primarily uses LZMA and LZMA2, which are designed for high-ratio data reduction. : The official