At my last workplace, where I was employed between 2003 and 2005, we had a web services system which used SOAP across two different programming languages (Java and C++) and had a potential future in another two (.Net and Python). We had some, what you might call, practical considerations. If you like, you can check the dates on the OASIS spec
Whether things are different now I truly don’t know, and I’m glad that I don’t. I wouldn’t go back to that fool’s gold if you paid me.