XSharp is FREE Software. Of course that does not mean that you can do with it whatever you want. We have set a couple of rules that determine what you can and cannot do with our software, so our software is released under a license.

In an ideal world we would have published all of our source code and binaries under a very open license agreement, such as the Apache License, just like how the Roslyn code is published.

However the reality is that there are people on this world that would like to take our source code and binaries and release this with minimal changes under their own name.

To prevent that from happening we have been forced to set some limitations to how you can use our product.

For any "normal" developer that uses XSharp to develop applications for end users this should present no problems.

The simplified version of the limitations means that you:

  • can only redistribute the 'runtime' components that are listed in the documentation. You can not redistribute our compiler. However when needed, you can ask your customer to download our compiler from this website
  • (when you are a FOX subscriber) have access to the compiler source code and may change and rebuild the compiler for internal use inside your company.
    However you are not allowed to publish or redistribute the (changed) compiler to your customers

We are convinced that you will find our license agreements fair and easy to work with.
If you have any questions about the licenses, please contact us at This email address is being protected from spambots. You need JavaScript enabled to view it.

ComponentNameShort summary of the license
The compiler binaries and runtime binaries XSharp Open Software License Agreement 1.0 This can be downloaded for free from our website. All you have to do is to create an account on this website.
  • You can download the components from our website
  • You can use the components for free both for commercial and personal use
  • You can only deploy the runtime components to your customers
  • OEM Licensing of the compiler binaries is only allowed when you have a separate agreement with XSharp BV
The source code to the runtime, visual studio integration and tools Apache License version 2.0 Everybody can access this public source code in our public repository on GitHub
  • You can download the source from our GitHub project
  • You can make adjustments to the source code both for internal use and also to redistribute the changed runtime binaries to your customers
  • If you have a contribution that you want to see included in a future version of XSharp you can send us a pull request on GitHub
  • XSharp BV decides which changes will be included in the main branch and which not.
The Roslyn part of the Compiler Source code Apache License version 2.0 This license applies to the Roslyn code that we have used and that you can also find on GitHub
The Antlr part of the Compiler Source code Antlr BSD License This license applies to the Antlr 4 source code that we have used and that you can find on GitHub
Our custom Compiler Source code XSharp Compiler Source code License 1.0

This license applies to our custom source code for the XSharp compiler.
Only registered members of the FOX program can access this source code in our private repository on GitHub

  • Subscribers may download this code and make changes for internal use
  • If you have a contribution that you want to see included in the main source you can send a pull request on GitHub
  • XSharp decides which changes to the source code will be included in the main branch and which not
  • If we accept your contribution and consider it a "substantial" change then we can recognize you as a Contributor
  • Contributors are allowed to distribute the program under their own license