The XSharp language plugin for ILSpy is coming back in two versions :
One for ILSpy V5.02; and another one for ILSpy V6.2.1 : Fonctionnaly, both versions are the same.
You can get these versions in the Downloads/General/Tools section.
Unzip the DLL in the same folder as the ILSpy Binaries and you're done.
If you are looking to the ILSpy binary, go to ILSpy binaries.
Now, when running ISpy, you can set the language as XSharp.
Don't forget that the full source code of the Plugin is available in the public XSharp Repository on Github; you can also view there the current state of developement of the tool.
ILSpy is the open-source .NET assembly browser and decompiler : By using ILSpy you cano view and decompile .NET assembly as XSharp Language.