Looking at which languages Xamarin supports, I saw that the folder:
C:\Program Files (x86)\MSBuild\Xamarin\Android
contains 2 files:
Xamarin.Android.CSharp.targets (for C#)
And Xamarin.Android.FSharp.targets (for F#)
(The 2 attachments in this message having .TXT extension at the end, in order to be able to attach them).
Because I have no knowledge at MSBuild level, I would like to ask if a corresponding file for X# can be produced.
At this moment we do not support Xamarin yet.
When we do then we will also release a similar targets file for X#.
However, supporting Xamarin requires more than just a special Targets file.
Xamarin also expects that the project system supports certain interfaces that we do not support yet.
We are planning to start working on extensions to the Visual Project System this Summer. Support for Xamarin, but also for .Net Core and portable class libraries are things we hope to add.
XSharp Development Team