Part I. Feature location and variability model extraction -- Chapter. 1. Feature Location in Software Variants Toward Software Product Line Engineering -- Chapter. 2. Feature & Variability Extraction From Natural Language Requirements -- Chapter. 3. Semantic History Slicing -- Chapter. 4. Feature Location in Models (FLiM): Design time and Runtime -- Chapter. 5. Search-Based Variability Model Synthesis from Variant Configurations -- Chapter. 6. Extending boolean variability relationship extraction to multi-valued software descriptions -- Chapter. 7. Machine learning for feature constraints discovery -- Part. II. Reengineering product line architectures -- Chapter. 8. Extraction of Software Product Line Architectures from Many System Variants -- Chapter. 9. ModelVars2SPL: from UML Class Diagram Variants to Software Product Line Core Assets -- Chapter. 10. Extraction and Evolution of a Software Product Line from Existing Web-Based Systems -- Chapter. 11. Re-Engineering Microservice Applications into Delta-Oriented Software Product Lines -- Chapter. 12. Understanding the Variability on the Recovery of Product Line Architectures -- Part III. Frameworks -- Chapter. 13. PAxSPL: A framework for aiding SPL Reengineering Planning -- Chapter. 14. Bottom-Up Technologies for Reuse: A Framework to Support Extractive Software Product Line Adoption Activities -- Chapter. 15. Systematic Software Reuse with Automated Extraction and Composition for Clone-and-Own -- Chapter. 16. Re-engineering Automation Software with the Variability Analysis Toolkit -- Chapter. 17. Managing Software Product Line Evolution by Filtered Editing: The SuperMod Approach -- Part. IV. Perspectives -- Chapter. 18. Challenges and Potential Benefits of Adopting Product Line Engineering in Start-Ups: A Preliminary Study -- Chapter. 19. Re-engineering Legacy Systems as Microservices: An industrial survey of criteria to deal with modularity and variability of features -- Chapter. 20. Evolution in Software Product Lines: An overview.