"These pages contain the essence of what it is to understand the world as objects and build software based on that understanding. You will be able to come back to these articles time and again, gaining new layers of understanding as you gain layers of experience." Kent Beck

• Part I. Structural Issues: 1. Modeling objects: using Binary- and Entity-relationship approaches; 2. Object types as objects and vice versa; 3. Power types; 4. Specifying structural constraints; 5. Toward a formalization of OO analysis; Part II. Dynamic Issues: 6. What is object state?; 7. Dynamic and multiple classification; 8. Events and their specification; 9. Approaches to finite-state machine modeling; Part III. Business Rules: 10. Business rules; 11. Using rules with diagrams; Part IV. Object Complexity: 12. Managing object complexity, Part I: classification and generalization; 13. Managing object complexity, Part II: aggregation; Part V. Object Aggregation: 14. Six different kinds of aggregation; 15. A foundation for aggregation; 16. A user-level model of aggregation; Part VI. Design Templates: 17. From analysis to design using templates, Part I; 18. From analysis to design using templates, Part II; 19. From analysis to design using templates, Part III; Part VII. The Process of Objects: 20. Method engineering; 21. User workshop techniques; 22. Object-oriented methodologies.