With the complete disappearance of our former competitor in the Xbase for .Net area (did you look at their website recently ?) we have decided that it is now time to make the source code to our compiler publicy available. After all we have nothing to hide, in fact we are very proud of what we have achieved in the last four years!
You will find the source code to the compiler (and Help and Manual documentation) on https://github.com/X-Sharp/XSharpDev.
This source code is shared under the Apache 2.0 license. Some source files still speak of the "X# compiler source code License". That will be changed in the coming weeks.
We have a small private repository still where the installer is located along with the certificates and keys. But that does not have anything you would need to rebuild the compiler.