Miguel de Icaza releases

At Microsoft Build today, we announced that we are re-releasing Mono under the MIT license and have contributed it to the .NET Foundation. These are major news for Mono developers and contributors, and I am incredibly excited about the opportunities that this will create for the Mono project, and for other projects that will be able to benefit from this.

Mono Runtime Released under MIT License

While Mono’s class libraries have always been available under the MIT license, the Mono runtime was dual-licensed. Most developers could run their apps on Windows, Linux or Mac OS X on the LGPL version of the runtime, but we also offered Mono’s runtime under commercial terms for scenarios where the LGPL was not suitable.

Moving the Mono runtime to the MIT license removes barriers to the adoption of C# and .NET in a large number of scenarios, embedded applications, including embedding Mono as a scripting engine in game engines or other applications.

Open Sourcing Proprietary Mono Extensions

Over the past 5 years, Xamarin has developed a number of proprietary extensions to Mono, including:

  • ARM64 port of the Mono runtime
  • Workarounds for bugs in some ARM chips
  • Use of Apple’s CommonCrypto to implement the crypto classes in the .NET API
  • Integration with X509 certificates on Apple platforms
  • Support for “Native Types” on Apple platforms
  • Generic Value Type Sharing
  • Offset tool to maintain the cross compiler

These have been integrated with the main Mono codebase, contributed along with Mono to the .NET Foundation, and are being released under the MIT license today.


Miguel de Icaza releases
Mono 4.2 is out in the [alpha channel](/download/alpha).

Mono 4.2 is out in the stable channel

Check out our release notes for details about what is new on Mono 4.2.1.

This is the second Mono release that integrates large portions of code from Microsoft’s open sourced .NET code.

This release was made up of over 2,338 commits since Mono 4.0.0 and as usual, it is our best release so far. Enjoy!



Miguel de Icaza releases

Mono 4.0 is out.

Check out our release notes for details about what is new on Mono 4.0.

This is the first Mono release that contains code from Microsoft’s open sourced .NET code. We are only getting started with this work. We are swiftly moving ahead in mono/master much more code that is being replaced and ported.

This version also is the first one to ship with C# 6.0 enabled by default. Learn all about C# 6.0 in only eight minutes on this presentation


Miguel de Icaza gsoc

Hey everyone! The Mono team is pleased to announce that we are a mentor organization in the Google Summer of Code 2015! This is the eleventh year of Summer of Code for us, and we’re really excited to work with a new group of students.

This is a great opportunity to spend the summer with a great community working on cutting edge open-source C# tools and frameworks. You can hone your development skills by working on large and complex codebases with experienced mentors, and get paid for your hard work too.

If you’re an eligible student, the application period runs from March 15-27. But don’t let that stop you from starting on your proposals! Feel free to introduce yourself to the community and mentors, talk about your ideas, and do some preliminary research to make your proposal as strong as it can be. If you’re feeling particularly ambitious, you could even get started on some quick bugfixes and patches to show off your skills; while this isn’t required, it is really helpful in seeing how you work and getting your name out in the community. Show us how excited you are about coding!

Same as last year, our project ideas and rules are available on our GSoC ideas page, and we’ll be updating the list as we come up with new ideas. Don’t let these ideas limit you though; if you have your own idea for a great project for the summer, put it in a proposal and send it our way. Or, if you can’t decide, you can always submit multiple proposals. Keep in mind, though, quality is better than quantity in this case.

Our project mailing lists should be your first stop for questions about contributing to Mono. There are many lists for different topics, but the main ones are mono, mono-devel and monodevelop-devel. For external projects, you should also contact the developers in their project mailing lists.

And of course IRC is where you can find everyone online, on the irc.gnome.org server. There’s the #mono channel for general Mono discussions, #monodev for Mono development, #monodevelop for MonoDevelop and Xamarin Studio, and #monosoc for Summer of Code-specific questions and saying “Hi” to your fellow students. Hang around a while after asking a question - we have mentors in many timezones so they may be asleep or busy when you visit.

If you’re not a student, you can participate in Summer of Code by helping the students feel welcome in our community! Or, if you’re interested in mentoring C# tools and libraries under the Mono umbrella, send an email to the Mono GSoC administrator at soc@xamarin.com.

To stay up to date with the applications process and the work of our students, follow us on Twitter and Google+. Good luck, and here’s to another great summer of coding!