DeltaJ 1.5: delta-oriented programming for Java 1.5. Delta-oriented programming (DOP) is a modular, yet flexible approach to implement software product lines. In DOP, a product line is implemented by a set of deltas, which are containers of modifications to a program. A delta-oriented product line is specified by its code base, i.e., the set of delta modules, and a product line declaration specifying the set of possible product variants. In this paper, we present DOP for Java 1.5 extending previous proof-of-concept realizations of DOP for simple core Java-like languages. The novel prototypical implementation DeltaJ 1.5 provides full integrated access to the object-oriented features of Java. The extensions include delta operations to fully integrate the Java package system, to declare and modify interfaces, to explicitly change the inheritance hierarchy, to access nested types and enum types, to alter field declarations, and to unambiguously remove overloaded methods. Furthermore, we improve the specification of the product line declaration by providing a separate language. We have evaluated DeltaJ 1.5 using a case study.