Why SOAP?

SOAP vs. CORBA

1. CORBA requires you to compile and distribute client stubs for each type of client that you have. This is not always practical particularly when you have many platform and language combinations or when you want to offer services to anonymous clients over the internet.
2. If developing web services then IIOP (CORBA's transport protocol) is not particularly firewall friendly. So if you want to offer services to clients over the Internet, while it will not be impossible with CORBA, you will have to overcome some firewall-related obstacles.
3. SOAP being XML-based: the fact that it is human readable and writable. This means you can easily read and manipulate the messages that are going over the wire. This is extremely useful when debugging.
4. SOAP could have reliable asynchronous delivery (CORBA does not)