The future of Mono and Unity
As we know, Unity does not use the latest and greatest Mono project code from http://www.mono-project.com, but an internally-customized version with some internal bug fixes.
The actual Mono tweaks made by Unity Technologies can be found in the following GitHub repository:
As an unfortunate consequence of how various components of the Mono Framework are licensed, Unity Technologies has only been able to update Mono on an infrequent basis. The occasions on which this task were accomplished was with the release of Unity 4, when they upgraded to Mono 2.6, and shortly afterwards version 2.6.5 back in mid-2010, which supports .NET 2.0/3.5 features. But, at the time of publication, ...