It uses the LZMA and LZMA2 algorithms, which provide a significantly better compression ratio than WinRAR's default settings.
You can create .exe files that extract themselves without requiring the recipient to have 7-Zip installed. BECWSVH.7z
Because the code is open-source (GNU LGPL), it is frequently reviewed by the community for security vulnerabilities. It uses the LZMA and LZMA2 algorithms, which