Microsoft just announced at //build 2016 that Xamarin will be free for all in Visual Studio, starting from the Community edition, and for OS X you can get Xamarin Studio Community Edition also for free. This is a step forward, but what's more important: Xamarin is licensed under MIT.
Previously parts of Mono (like class libraries) have been licensed under MIT, but the actual runtime was under LGPL and by paying you could get it into your commercial products. Xamarin also has done many proprietary extensions for it so you couldn't just grab something and make it run nicely on Android or iOS. Now that everything is MIT you can do whatever you want with it.
I'm hoping this will allow Mono/Xamarin to evolve faster and get into the point where it's a stable, worthwhile environment. I did blog about the current state of Xamarin and how it is quite crappy to use. I hope Microsoft does focus on this and doesn't go into the oh so familiar "well it's open source, we'll let the community take care of it" mode that some other companies have done. I don't think they will. This is an important move to get .NET to even broader user base and if this is not handled properly it will fail.
I'm looking at you, Microsoft. Take Xamarin to the same level as .NET is on Windows and Visual Studio development is normally. No more Xamarin Studio on Windows, no more buggy breakpoints, crashing IDEs, hanging runtimes. No more half done stuff. Make it great and make it fast. I trust you.