Microsoft transitions Mono project stewardship to WineHQ organization

The Mono Project, a key component of the .NET ecosystem since its start in 2001, is undergoing a transition. Originally created to allow developers to easily build cross-platform applications, Mono has been instrumental in extending .NET to various operating systems, including Android, iOS, and Linux.

After Microsoft acquired Xamarin in 2016, it became the steward of the Mono Project, continuing its development. The last major release of the original Mono Project occurred in July 2019, with only minor patch releases since, the most recent in February 2024.

Now, the WineHQ organization will take over stewardship of the Mono Project. The WineHQ team will maintain the upstream repository at wine-mono / Mono on GitLab. Existing source code repositories will stay available, though some may be archived, and binaries will be accessible for up to four years.

In parallel, Microsoft has been working on a modern fork of the Mono runtime within the dotnet/runtime repository. This version has become the preferred platform for .NET workloads, and the transition to this updated runtime is now complete. Microsoft advises active Mono users and maintainers of Mono-based application frameworks to migrate to .NET, which incorporates work from this fork.

The Mono Project has played a vital role in the history of .NET development, being the first .NET implementation to support multiple operating systems. Microsoft and the developer community acknowledge the contributions that Mono developers have made over the years.