The name was changed from Eiffel# to EiffelForDotNet? as the first implementation (Eiffel#) was a subset of real Eiffel and as such a different language. Now that they managed to map all Eiffel constructs to the CLR, they call it EiffelForDotNet?.
See also: MicrosoftDotNetCommonLanguageRuntimeCategoryProgrammingLanguageCategoryEiffel