SharpKit is free under GPL, that means that if you're open source you can use it freely, for commercial purposes please refer to our licensing/pricing section.
SharpKit was designed to be a nonintrusive, pure compile-time solution with minimal impact during development and zero impact during production.
No. SharpKit compiler is an executable that can be used with or without Visual Studio.
It is up to you. SharpKit provides standard support for many C# language features without including any additional files. Advanced support for features such as reflection, LINQ and generics require a small include of the SharpKit JS Kernel (about 60K compressed).
You can, but you don't have to.
Yes. SharpKit has a limited support for yield, and currently doesn't support explicit interface implementation and custom (non-native) structs.