Remoting vs XML Web Services

So which to use?

They share alot of similarities but also alot of differences.

XML Web services built using cross-platform standards based on xml messaging. The are execute by the ASP.NET runtime thus gaining ASP.NET features like output caching. An important point is that it is fundamentally stateless. The best uses for XML web services is when cross platform boundaries or trust boundaries are required.

Remoting is a .NET specific technology for building distributed objects. It supperceeds DCOM. Perfect for in-house systems that need to communicate and are built using the same .NET platform. It allows for different types of communication, such as sharing binary messages to lean TCP/IP connections. If you want stateful objects and bidirectional communication via callbacks then this is your technology. It also allows you to send custom .NET objects over the wire.