Systems Application Architecture (n)~ An IBM-developed standard for the appearance and operation of application software that will give programs written for all IBM computers—mainframe computers minicomputers and personal computers—a similar look and feel. SAA defines how an application interfaces with both the user and the supporting operating system. True SAA-compliant applications are compatible at the source level (before being compiled) with any SAA-compliant operating system— provided the system is capable of furnishing all the services required by the application. systems integrator (n)~ A person or organization that develops enterprise applications by integrating hardware or software provided by independent vendors.