Need a simple web service for Linux

Need a simple web service to be constructed for Linux. The service has already been made for C# so I can send you the interface, which must be identical for the Linux version. The service must be activated, either on startup of the Linux instance or by making a web service call to the Linux machine. Instructions must also be given for how to install the service to the Linux machine, as my Linux knowledge is very limited. I dont care what language it is written in, as long as it runs on a Unix/Linux platform. The service only has one method so it should be very easy for a seasoned Linux programmer.