I've gotten a new appreciation for OOP (and TDD) after reading "Growing Object-Oriented Programs Guided By Tests." It's made me start thinking of programs more

I've gotten a new appreciation for OOP (and TDD) after reading "Growing Object-Oriented Programs Guided By Tests." It's made me start thinking of programs more as multicellular organisms, or communities, where each part is responsible for a particular task. I think this is the core genius of OOP. It's not about classes or (Java) interfaces, it's about programs being communities of cohesive individuals with well-defined communication protocols. edit to add: I think another key difference is in increasing the level of abstraction that you think about your program. You want to build a layer where you just say what should happen (the "declarative layer"), and keep that separate from the idea of how it should happen (the "implementation layer").