7z is a new and open architecture archive format developed by Igor Pavlov and based on LZMA compression algorithm. Both LZMA and the utility for handling 7z archives, 7-Zip utility are released under GNU LGPL license which mean is free for commercial or personal use on any computer.
A few of the most important features of 7z format are:
- High compression ratio
- Strong AES-256 encryption
- Open architecture
- Unicode file names
- Supporting files with sizes up to 16000000000 GB
The utility created for handling 7z archives, 7-Zip is an open source software created aswell by Igor Pavlov assuring a high compression ratio for processed files and supporting many archive formats:
- Packing / unpacking: 7z, ZIP, GZIP, BZIP2 and TAR
- Unpacking only: ARJ, CAB, CHM, CPIO, DEB, DMG, HFS, ISO, LZH, LZMA, MSI, NSIS, RAR, RPM, UDF, WIM, XAR and Z
The utility works on all versions of Windows, including Windows 7, 32 and 64 bits, bringing great features as :
- Strong AES-256 encryption in 7z and ZIP formats
- Self-extracting capability for 7z format
- Multilanguage support
- Integration with Windows Shell–Context menu or “right-click” menu
- Split and combine files
- Benchmark tool
7-Zip has a higher compression ratio, than many other commercial products like WinZip and even a higher speed of processing files and more, I must add the simple and intuitive interface and the extreme ease of using it via context menu(right-click) menu.
One of the most interesting and useful feature is the unpacking of NSIS(Nullsoft Scriptable Install System) installers, a professional open source system to create Windows installers. This feature is useful especially for who wants to know what files are inside an installer and in particular cases when somebody download software from untrusting sources(warez). Very often hackers rebuild the programs installers including a trojan backdoor in it, which is executed concomitantly with the original installer setup, resulting a computer infection. If the antivirus gives a detection alert on a particular installer setup and this is build using NSIS, the trojan can be revealed and isolated for further analysis by unpacking the modified installer with 7-Zip archiver.
The free 7-Zip archiver is totally recommended for use, replacing with success commercial programs and working great on the newest Windows versions like Windows 7 or Windows 2008, both 32 and 64 bits architecture.