Our work is concerned with an enriched perspective of what constitutes developer contribution in software infrastructures supporting incremental development and distributed software projects. We use the term “contribution” to express the combination of all the actions a developer has performed during the development process and propose a model for calculating this individually for developers participating in a software project. Our approach departs from the traditional practice of only measuring the contribution to the final outcome (the code) and puts emphasis additionally on other activities that do not directly affect the product itself but are essential to the development process.We use the Open Source Software (OSS) context to take advantage of the public availability of data in software repositories. In this paper, we present our method of calculation and its system implementation and we apply our measurements on various projects from the gnome ecosystem.