Install xdelta with Homebrew

Project links

• Homepage

Commands and aliases

• xdelta3

Project history

The xdelta3 README carries copyright years beginning in 2001 and describes the project as a command-line interface and source distribution for VCDIFF differential compression. RFC 3284, published in June 2002 and co-authored by Josh MacDonald, standardized the VCDIFF generic differencing and compression data format that xdelta3 implements.

The public Git history in the current repository starts with 2006 source snapshots and concentrated work around large-file and checksum behavior. By the 3.0 series, xdelta3 had become the maintained branch users generally meant when they installed an xdelta package.

The current upstream documentation presents xdelta version 3 as both a C library and a command-line tool, with the maintained 3.2.x series using CMake, optional liblzma secondary compression, static release binaries, and an embeddable libxdelta3 API.

Adoption history

xdelta adoption has always followed the practical need to ship changes without shipping whole files: game patches, ROM patching communities, software update systems, and package workflows all benefit from binary deltas. Its VCDIFF basis matters because the delta format is documented outside a single implementation.

Package availability is broad in the input facts: Alpine, Homebrew, Debian/Ubuntu, Fedora, MacPorts, Nix, Arch, Scoop, and openSUSE-family packages all carry xdelta or xdelta3 names. That cross-platform packaging matches upstream release binaries for Linux, macOS, and Windows.

How it is used

The core command pattern is encode with an old source file, a new target file, and an output delta, then decode later with the same source and the delta to reconstruct the target. The upstream README shows xdelta3 -e and -d examples with -s for the source file.

Modern xdelta3 can also be embedded as a library through xdelta3.h and build-system integration. This matters for software that wants VCDIFF behavior internally rather than shelling out to the xdelta3 executable.

Why package nerds care

xdelta is a package-nerd staple because it sits at the intersection of compression, patch distribution, archival workflows, and reproducible binary transformations. It is small enough to be a CLI utility, but backed by a standards-track format and decades of compatibility expectations.

For package indexes, it is also a naming lesson: users may search for xdelta, xdelta3, or VCDIFF depending on platform and era, while the executable commonly exposed by modern packages is xdelta3.

Timeline

• 2001: xdelta3 README copyright years begin, indicating early xdelta3 development.
• 2002-06: RFC 3284 publishes the VCDIFF data format.
• 2006-08-27: First source snapshot in the current GitHub repository history.
• 2015-03-30: v3.0.9 tag in the long-lived 3.0 release line.
• 2016-01-07: v3.0.11 and v3.1.0 tags.
• 2026-06-20: v3.2.0 tag and maintained 3.2.x series documented upstream.

Related projects

• VCDIFF/RFC 3284: standardized delta format implemented by xdelta3.
• XZ Utils/liblzma: optional secondary compression support in upstream builds.
• BLAKE3: used by modern xdelta3 armor mode for whole-file verification.
• bsdiff and courgette-style binary patchers: related binary-delta tools with different formats and tradeoffs.

Sources

• Git history and tags: https://github.com/jmacd/xdelta
• README, jmacd/xdelta: https://github.com/jmacd/xdelta#readme
• RFC 3284: https://www.rfc-editor.org/rfc/rfc3284
• Xdelta documentation: https://jmacd.github.io/xdelta/
• xdelta3 README: https://github.com/jmacd/xdelta/blob/main/xdelta3/README.md