> adapt it to your needs If it's a feature that can be cleanly added into the architecture - i.e. it's just filling in a gap. But if you have to modify the wh

> adapt it to your needs If it's a feature that can be cleanly added into the architecture - i.e. it's just filling in a gap. But if you have to modify the whole thing in a way that doesn't quite fit... it's a nightmare. Even with your own code, it's simpler to start from scratch with a clean slate. Also Alan Kay's extreme position: "those who can create their own [libraries], should"