Windows Communication Foundation versus older web services (.asmx) is a question that really bugged me today. Why? Because I was merrily developing an application using a SOAP Client and asmx files, and I stopped mid-flight, thinking to myself am I doing the right thing? Should I be adjusting my approach? So I set about Googling on the topic and came across several resources or opinions, but one thing that did stand out for me was that WCF web service do not need to be attached to IIS to work. Normal (dare I say legacy) web services (asmx) only use HTTP and therefore can only be run if its attached to a process that can run HTTP. WCF is not so limited, in fact it supports multiple protocols. WCF is an ‘umbrella’ technology that encompasses several other technologies. Decision was made, I will not easily use older web services again if I don’t have too.