This book constitutes the thoroughly refereed post-conference proceedings of the 7th International Conference on Fundamentals of Software Engineering, FSEN 2017, held in Tehran, Iran, in April 2017. The 16 full papers presented in this volume were carefully reviewed and selected from 49 submissions.

Implementing Open Call-by-Value.- Debugging of Concurrent Programs Using Counterexample Analysis.- Bisimilarity of Open Terms in Stream GSOS.- Composing Families of Timed Automata.- A Core Calculus for Multi SPLs.- Translating Active Objects into Colored Petri Nets for Communication Analysias.- Synthesizing Parameterized Self-Stabilizing Rings with Constant-Space Processes.- Flexible Transactional Coordination in the Peer Model.- Using Swarm Intelligence to Generate Test Data for Covering Prime Paths.- LittleDarwin: a Feature-Rich and Extensible Mutation Testing Framework for Large and Complex Java Systems.- TCE+: An Extension of the TCE Approach for Detecting Equivalent Mutants in Java Programs.- Quality-Aware Reactive Programming for the IoT.- Purpose-based Policy Enforcement in Actor-based Systems.- Automatic Transition System Model Identification for Network Applications from Packet Traces.- Gray-Box Conformance Testing for Symbolic Reactive State Machines.- Model Checking of Concurrent Software Systems via Heuristic-Guided SAT Solving.