ABAP (Advanced Business Application Programming) is a programming language for developing applications for the SAP R/3 system, a widely-installed business application subsystem. The latest version, ABAP Objects, is object-oriented programming. SAP will run applications written using ABAP/4, the earlier ABAP version, as well as applications using ABAP Objects.
SAP's original business model for R/3 was developed before the idea of an object-oriented model was widespread. The transition to the object-oriented model reflects an increased customer demand for it. ABAP Objects uses a single inheritance model and full support for object features such as encapsulation, polymorphism, and persistence.