I’m not sure whether you’re asking about cXML or xCBL, but WM handles both. You can simply import the respective DTD or schema (search the forums for issues and workarounds in doing this with previous IS versions)
Alternatively, if you need to exchange documents using the full protocols defined by CommerceOne or Ariba, you can simply install the webMethods adapters for these. The CommerceOne OnRamp adapter gives you xCBL and CommerceOne envelope support - it’s WmxCBL.zip package contains the record definitions for xCBL 2, xCBL 3 and xCBL 3.5. The Ariba OnRamp adapter support Ariba cXML 1.2+ .
#webMethods#Integration-Server-and-ESB#Adapters-and-E-Standards