The sourcecode for XSharp is available on GitHub. Look at https://github.com/X-Sharp/XSharpPublic for the sourcecode for our runtime and tools. The source code for the compiler is in a private repository on Github. If you are a subscriber and would like access to the compiler source, then you need to create a GitHub account and contact and tell us your Github username. We will then grant you access to the compiler source.
Like most Github projects you will have read only access our our repositories. If you have made changes to the source code that you would like to share with others and would like to see included in the main branch, please send us a so called "Pull Request". We will review your code changes, and we will integrate your changes if think they are usefull to others and when they to not break other code.
Working with Github may be a challenge in the beginning (it was for some of our team members as well). There are some excellent books and ebooks about this available that may help you to get started/.
If you want to do more than occasional changes, please let us know. In that case we may also grant you driect read/write access to our repositories.