The End of an Era: Apple Ditches Ancient RSYNC for OpenBSD’s OpenRSync

For years, MacOS users have relied on the RSYNC tool, a staple in Unix-like systems, for efficient file transfer and synchronization. However, Apple’s commitment to an outdated version, 2.6.9 released way back in 2006, has been a point of contention. While RSYNC has evolved significantly,with version 3.0 arriving in 2008, Apple has remained steadfastly behind the times – until now.

License Limbo: GNU GPL and Apple’s Reluctance

The primary reason for Apple’s reluctance to upgrade RSYNC appears to stem from a shift in licensing. Initially released under the GNU GPL 2, newer RSYNC versions adopted the GNU GPL 3. Apple, seemingly unwilling to adhere to the updated license’s conditions, chose to maintain the aging version, applying security patches to a codebase nearly two decades old. This decision meant MacOS users missed out on the performance enhancements and features available in more recent RSYNC iterations.

The transition to GNU GPL 3 introduced stricter requirements, especially concerning the distribution of software that incorporates GPL-licensed code. This likely presented challenges for Apple’s proprietary ecosystem.

A New Dawn: MacOS Sequoia Embraces openrsync

With the release of MacOS Sequoia, Apple has finally addressed the RSYNC issue. The outdated RSYNC version has been replaced with OpenRSync, an implementation originating from OpenBSD. This strategic move allows Apple to circumvent the GNU GPL license altogether, as OpenRSync operates under the more permissive ISC license, a member of the BSD license family. This change allows Apple to provide a more modern RSYNC solution without the licensing constraints of GNU GPL 3.

Seamless Transition, partial Compatibility

Starting with MacOS 15.4, the rsync command now acts as a symbolic link to openrsync, ensuring a smooth transition for users accustomed to the old command. While OpenRSync aims for compatibility, documentation indicates that it only supports a subset of the features found in the latest RSYNC versions. Users with complex RSYNC workflows should test their configurations to ensure compatibility.

According to OpenBSD’s official documentation, OpenRSync prioritizes core functionality and security, possibly omitting less frequently used or experimental features found in the full RSYNC suite.

Implications and Future Outlook

Apple’s move to OpenRSync represents a meaningful shift in its approach to file synchronization on MacOS. By adopting a BSD-licensed alternative, Apple gains greater control over the software’s integration within its ecosystem. Though, users should be aware of potential compatibility limitations and consider alternative solutions if OpenRSync does not meet their specific needs. The long-term impact of this change remains to be seen, but it undoubtedly marks a new chapter in the evolution of file synchronization on MacOS.