Libarchive Multi-Format Archiver

Libarchive is a portable C library that can read and write streaming archives in multiple formats and with multiple compression algorithms. Originally created by Tim Kientzle in 2003 as part of the FreeBSD project, libarchive has over 3,200 stars as of 2026 and is the core compression and archive library used by FreeBSD, macOS, and many Linux distributions as the backend for the bsdtar and bsdcpio utilities. Key features include: archive format support for reading (tar, pax, cpio, ISO9660, zip, 7-Zip, xar, lha/lzh, rar, cab, mtree, AR, and raw formats) and writing (tar, pax, zip, 7-Zip, xar, cpio, ISO9660, mtree, and raw), compression algorithm support (gzip, bzip2, lzma, xz, lz4, zstd, and compress via built-in or system libraries), streaming architecture (reading and writing archives as sequential streams without needing random access, enabling processing of network streams, pipes, and very large archives), in-memory and file-based operations (processing from file descriptors, FILE pointers, memory buffers, and custom callbacks for full I/O flexibility), format auto-detection (automatically identifying archive format and compression from data content), filter chaining (applying multiple compression and decompression operations in sequence), fine-grained control (selecting specific compression levels, format variants, and entry attributes), hardlink and symlink preservation (maintaining file system relationships within archives), xattr and ACL support (preserving extended attributes and access control lists), sparse file handling (efficient storage of sparse files within archives), encryption (zip format AES encryption support), and the bsdtar utility (a command-line interface combining tar functionality with libarchive format support, used as the default tar on macOS and FreeBSD).