使用什么Web服务/接口？

We are designing a system with C/C++ back end server and C# .NET front end. We would like to provide a web interface similar to C# .NET front end. Can you please suggest the best way to do it? e.g. Whether to embed the web server in back end server itself? How to have maximum common code between in .NET and web interface to minimize the maintenance, etc. Thanks in advance!We are designing a system with C/C++ back end s