Evolution of understandability in OSS projects

Empirical papers on open source software should try and formulate reasons for successes as Linux, Apache and some other flagship projects. What we need to understand about this topic is on the process of producing software through cooperation of different efforts. Albeit many success reasons for these projects are inherently due to the application domain that the project develops, architectural and conceptual views of the code have to be considered as key factors when considering community efforts and joint decisions. We focus our attention on what is perceived of a source code when investigating its structure. We do this considering that structure as a proxy for the conceptual architecture of the application. A metric is developed based on some current assumptions, and it is tested over a sample of open source projects. What is interesting to note, is that refactoring efforts are clearly visible when intended as reduction of complexity of source code. Our second observation is that, based on what an open source software currently does, i.e. its application domain, there's a threshold value that several projects tend to.