Why it _shouldn't_ be SOAP?
It's a perfectly fine protocol, with a rigid schema and mature code generation support for all relevant languages. It's not the sexiest protocol, but it gets the job done.
And what are the alternatives? JSON schema?
And what are the alternatives? JSON schema?
ASN.1? It's even more mature, and the de-facto DER/BER encoding is far more efficient to generate and parse than anything XML-based.
I think the biggest problems with SOAP was the implementations, never the standard. WCF...
An adaptation of PEPPOL (also XML, but at least standardised)?
> mature code generation support for all relevant languages.
Heh, "relevant languages" is kind of an interesting term there. If the relevant language is Java then sure, it's fine.
Some popular modern languages (ie Go) don't have good SOAP support (yet). At least not to the point of being able to point them at WSDL/XSD specs and have everything auto-generated. :(