Recovering variability information from the source code of similar software products

We developed a reverse engineering technique, named Variant Analysis, aimed for recovering and visualizing information about commonalities and differences that exist in the source code of multiple similar software systems. The delivered information is available on any level of system hierarchy, from single lines of code up to whole software systems. The technique scales well for many compared system variants and for large software systems. We think Variant Analysis could be useful for practitioners who need to identify source-level similarities between many potentially unknown software systems - either with the primary goal of understanding the variability in the systems, or with a further motivation such as preparation for an extractive introduction of the product line approach.