Not Just IBM Products Supported
I was supporting Oracle Application Server on Sun (then) Solaris servers when IBM (Global Services) laid me off 11 years ago, and they still kept a lot of such folks (along with WebLogic admins, and some of those in Brazil thought they could support OAS satisfactorily...) after that round. Their contract support would hire whatever skills the customer demanded. Dunno about now, but seems they still attempt to do something of that sort, if not so thoroughly...