REST, please. You can generally bootstrap a REST client from any language with basic HTTP and XML/JSON/… libs (ie. basically every language.) On the other hand,

REST, please. You can generally bootstrap a REST client from any language with basic HTTP and XML/JSON/… libs (ie. basically every language.) On the other hand, doing SOAP without a dedicated library is a path to pain and suffering, and not every language has such a library. Additionally, the complexity makes it that much harder to find a reliable library. (Python, for instance, has a SOAP lib, but it's old and tends to not play at all nicely with .NET's automatic SOAP services. Last time I tried to do that it ended with wailing and gnashing of teeth.)