Here. "Eiffel ENViSioN!TM is a plug-in for Visual Studio .NET - its icon appears in the same place the other languages do, but that's where the similarity ends. Eiffel ENViSioN! enables you to use the powerful features of the Eiffel language, including Design by ContractTM (a means for making super-robust software, native only to Eiffel), multiple inheritance, generics, and many others. You can use it to be more productive than you ever dreamed. (Eiffel users report that they can produce 3-10x as much high-quality software as they can using any other language and/or tools.)"
Eiffel has two features that I wish C# had: design by contract and generics. While the free edition is limited when compared to the non-free edition, it won't expire. If you'd like to see how Bertrand Meyer thinks you ought to program w/o leaving the comfort of .NET, check it out.