Is JAXM an alternative for the Apache SOAP implementation? Or is it a kind of a standard API which can use Apache SOAP as well, just like JavaMail API can use POP3/IMAP protocol at the backend?
JAXM and Apache SOAP are similar in many ways and can be used to solve many of the same problems. However, there are a few differences:
Apache SOAP is based on IBM's SOAP4J implementation of the SOAP submission to W3C. Apache SOAP comes with source code that is distributed under the Apache Software License. Apache SOAP supports scripting-language authoring services and primitive data-type encoding/decoding.
JAXM is intent on providing an XML framework for standards-based messaging protocols that is agnostic about the underlying abstraction. The JAXM specification includes the notion of messaging Profiles where a profile represents a standard protocol, such as ebXML Transport/Routing & Packaging (TR&P). Profiles provide additional functionality to the SOAP protocol.