When come to creating Web Service client, we all know that there is a menu option called "Add Web Reference". This works great until we realized the we want our client to implement our domain interface and takes/returns our domain objects.
Spring.Net solved this problem by generating a dynamic proxy at runtime that implements the domain interface, but the startup performance becomes a big problem. SGen cannot pre-generate XmlSerializer for those dynamic proxies simply because they don't exist at compile time.
Web Service Source Code Generator does what Spring.Net do in compile time. So that we can have our Web Service client implements our own domain interface and still startup fast.