Feature Language Extensions (FLX) and AspectJ are two sets of programming language constructs designed to enable the programmer to modularize... Show moreFeature Language Extensions (FLX) and AspectJ are two sets of programming language constructs designed to enable the programmer to modularize interacting features, or equivalently crosscutting concerns, that cannot be modularized with a main stream programming language. The two approaches are quite di erent. The purpose of this thesis is to compare how e ective they are in feature integration, such as whether the already developed features will need to be modi ed. The study was conducted by integrating a set of features of the familiar computer blackjack game. The blackjack game is interesting because it has features that will execute some programs of the basic game iteratively and recursively. We found that with AspectJ we need to modify existing feature code or repeating feature code under certain integration scenarios. We discuss the underlying reasons why they occur and in some cases suggest methods to overcome them. M.S. in Computer Science, July 2014 Show less