7-Zip vs bzip2

7-Zip is a file archiver for Windows, Linux, and macOS, offered at free with no registration or payment required. It creates and extracts 7z, XZ, BZIP2, GZIP, TAR, ZIP, and WIM archives, and can extract additional formats such as RAR, ISO, and VHDX. The 7z format uses LZMA and LZMA2 compression, and AES-256 encryption is available for 7z and ZIP files. Other listed capabilities include split archives, archive repair, portable use, and command-line tools. The Windows version includes Shell integration, a file manager, a command-line version, and a FAR Manager plugin. The software is open source; most code is under the GNU LGPL, with some under BSD licenses and an unRAR restriction applying to some parts. The maker says it can be used in commercial organizations without payment. It is localized in 87 languages. Developers can use the LZMA SDK, which includes documentation, samples, headers, libraries, and tools for applications using LZMA compression.

bzip2 is a free data compressor for creating and reading compressed files. It provides command-line tools and supports BZ2 (.bz2), BZ (.bz), TBZ2 (.tbz2), and TBZ (.tbz) formats. The maker says its compression typically comes within 10% to 15% of the best available PPM-family techniques, while running around twice as fast for compression and six times faster for decompression. Its limited media-error recovery may allow undamaged portions of a damaged file to be decompressed. The separate libbzip2 library lets programs read and write .bz2 files or compress data in memory. Command-line flags resemble GNU Gzip's, and the distribution should compile without modification on Unix and Win32 systems. bzip2 dates to 1996 and is open source under a BSD-style license. The official site lists version 1.0.8 as stable and offers source code, not executables. Building has a good chance of success with an ANSI C compiler and at least 8 megabytes of spare memory; the source tarball includes documentation in several formats.