MOVis: A Visual Analytics Tool for Surfacing Missed Patches Across Software Variants

Abstract

Clone-and-own development produces families of related software variants that evolve independently. As variants diverge, important fixes applied in one repository are often missing in others. PaReco has shown that thousands of such missed opportunity (MO) patches exist across real ecosystems, yet its textual output provides limited support for understanding where and how these fixes should be propagated. We present MOVis, a lightweight, interactive desktop tool that visualizes MO patches between a source and target variant. MOVis loads PaReco's MO classifications and presents patched and buggy hunks side-by-side, highlighting corresponding regions and exposing structural differences that hinder reuse. This design enables developers to quickly locate missed fixes, understand required adaptations, and more efficiently maintain consistency across software variants. The tool, replication package, and demonstration video are available at https://zenodo.org/records/18356553 and https://youtu.be/Ac-gjBxHJ3Y.