Here is a way to check what version of boo your script is running in.
Boo now has a BooVersion builtin:
The old way to do that is to check the version of the Boo.Lang.dll assembly. We find the assembly by getting the Assembly property of the builtin List type contained in Boo.Lang.dll.
Checking if BooVersion is higher than certain version
To see if you are running in a specific version or higher, use code like this:
You can also see what version of .NET or Mono the runtime is using: