as a interface in your webservices, it's invoked by anyone, it also can use EJB or invoke any EJBs in your interface of webservices, for out of programme such Delphi,VB and so on, you can find the function in the IDE like:
Delphi IDE->Import Webservices from URL
JBuilder IDE->Import Webservices from URL
(You should point the wsdl address, just like the xxxxWebservicesInterface?wsdl)
it will build some class for your programm, good luck.