File archiver by Igor Pavlov built around the open 7z format and the LZMA algorithm, offering some of the strongest general-purpose compression ratios available. Its compression code is in the public domain and used far beyond the program itself.
The Preservation Rating scores how well this entry is archived — not how good the software is. It's calculated automatically from what's already on this page: working mirrors, documentation, a reproducible build, a clearly identified license, and complete metadata. Nothing here is entered by hand; it updates itself whenever the entry changes.