This is fantastic! This actually puts the engine ahead of Unity in terms of scripting since those guys target a rather outdated version of C#/Mono. Now I can't wait to play around with Godot.
(Modern) C# is my favorite language, but I've been looking into F# recently. Wonder if someday that might be an option in Godot as well. Given how both languages compile to the same binary format, there have been workarounds to use it in Unity even though it's not officially supported.
I believe Unity was investigating embedding the .NET Core runtime instead, for performance gains due to a better GC and better JIT.
Therefore I find it very odd they chose to use the Mono runtime. It sounds to me the .NET Core runtime is a much better choice, since the underlying CLR is in the basis the same as the .NET Framework CLR, including the Ryujit and all the other goodies.
You don't have to use the C# features of Godot. You can still use GDScript to code your game in, or GDNative with any extending language like D, Go, or Rust, so long as you find bindings for them. I wouldn't worry about Microsoft being owed favors, I'd worry more about actual licensing, and if it wasn't for Microsoft (or so I suspect) Mono would still not be as openly licensed as it is now[0].
Note how Microsoft was mentioned for their license change (why would that be if Microsoft had nothing to do with the change, wondering if buying out Xamarin gave them power over making Mono more open), and it was announced at the annual big Microsoft event no less. I'm all for yelling at Microsoft when they screw up, but they're doing good things with .NET and C#.
>As of alpha2, Godot is using Mono 5.2 and C# 7.0 is supported.
This is an explicit dig at Unity, which is still(?) on Mono 2.x and C# 3.5 owing to their custom IL2CPP toolchain (with Mono 4.x / C# 6 in beta for the editor only).
It is a valid bragging point for Godot that probably doesn't have much to do with Unity which had been trapped in an old version of mono for licensing reasons (not because of the toolchain - it was the other way around). Unity has been able to start updating now that Microsoft opened up and bought Xamarin), and is now offering Mono/.Net 4.6 and C#6 and I assume will continue to modernize.
Is Mono not dying due to .NET core? It seems to be popping up in a few new places but I would have thought new projects would be avoiding it.
The last thing I want is any dependency on MS tooling as they've shown everything they release will include telemetry. I'm just getting started with game dev and I really like Godot, but if the future is going to require MS anything, I'm going to jump ship.
Mono is still supported. .NET core and Mono solve different problems - for example (this surprised me), unlike Mono and the windows .NET Framework, .NET core can't just run random .NET executables you download off the internet. You have to build a core-targeted project from source. Mono also handles cross-platform scenarios like mobile & mac frontend apps right now that .NET core won't be a good fit for in the near future.
Mono, .NET Framework, .NET Core, Xamarin.<Platform>, etc are all just different implementations of .NET Standard. I believe .NET Framework is a superset of Core.
They can all run code targeted at Standard but all have slightly different libraries on top of Standard. Mono was originally was intended to be a cross platform stand-in for .NET Framework which is why they can mostly run the same code. I believe Mono and Framework are slowly merging together.
I don't think this is true. Framework for example can only reference standard libraries as of 4.6.2. Up until dotnet core 2.0, core was very much an incompatibile subset of framework - even with 2.0 it would be better characterised as a cross platform rewrite of the net framework.
I have bad news for you; Mono 5.0 launched with Roslyn which I believe is what brings C#7 support. Roslyn is of course a MS project. Ditto for MSBUILD.