 Thank you very much. So the Ecclesiastes principle is a phrase which was coined by a friend of mine, Simon Phipps, to describe a phenomenon that he was seeing in open source communities that he's worked in. So Ecclesiastes 1.9 says, what has been will be again. What has been done will be done again. There is nothing new under the sun. And what he noticed was that we were relearning lessons that have been learned in previous areas before. Now, in the open source world, it was very easy for us to think that we're trailblazers. We're going boldly where no one has gone before. Everything is new. Computing has only been around for 50 or 60 years. The web for about, what, 30 years, 25, open source, 30, 35 years. So it's easy for us to fall into the trap of thinking that we have nothing to learn from the past. And yet, like Ruth said, building software is just building stuff. We're just members of communities. And people have been doing that stuff for a really long time. And in my experience, everywhere we go, we find traces of people who have gone before. We find that there are people who've studied communities, building things, the way that people interact with each other. And we can learn from them. And so I want to give you two examples today of areas which are seemingly unrelated to open source, where I think we have lessons to learn from the past. First is from the world of architecture. And the second is from the world of city planning, which are kind of related. OK, so the first example is from a series of books called The Oregon Experiment by Christopher Alexander. It's a pattern language. Excellent book. I would recommend it to anyone. It was the inspiration for the Gang of Four design patterns later on. And what a pattern language does is he examines, Alexander does in this book, is he examines traits of successful buildings, regions, and communities. And one of the traits, one of the design patterns that he notices is the intimacy gradient. The idea of the intimacy gradient is that a building that feels comfortable goes from most public to most intimate space. You shouldn't, for example, in a restaurant, have people going through the kitchens to get to the customer toilet because they feel uncomfortable, because the kitchens are a private area. So this is my house. As it was originally, there's been some extensions since. But it's a standard three-bedroomed house with living in kitchen area, a garage, garden, and front gate leading out onto the street. And if we overlay the intimacy gradient on top of this, we can see that the house feels right. When you're coming in through the front gate, we're going through a patio area, which is kind of a little bit more intimate, and then into the living room and dining area. And we don't have to, for example, go through the bedrooms to get to the toilets, right? So communities, and the lessons I think we can learn from this, communities have their intimacy gradient as well. We have all of these ways that we can talk to people, whether it's by broadcasting on a website or on a mailing list, public forum, through to private email. And each of these has their place. Each of them needs to be kept in balance. We can't, for example, do too much in private or force people who are uncomfortable with public communication into public areas without disturbing the force in some sense. And it's also, for example, you shouldn't have people sending email to request access for a bug tracker, for example. The second example from the world of city planning, the death and life of Great American Cities by Jane Jacobs, really a pioneer in this area. I recommend this book to anybody who's interested in communities. And one of our key ideas in city planning is that to have successful neighborhoods, you need to have mixed primary and secondary uses. So primary uses are the reasons why you would go someplace, to shop, to live, to work. And those mixed primary uses are what allow you to have constant activity in an area. And that creates the demand and the constant flow of people which keeps an area safe and allows you to have that diversity of secondary uses that make neighborhoods nice to be in restaurants, theaters, parks, playgrounds, and so on. And communities also need these mixed primary and secondary uses. The classic one is professional diameter. We need, in successful communities, we need a mix of people who are working full time on the projects and a mix of people who are working on a diameter in their spare time so that you don't have the project shutting down on the weekend. Geographical diversity is also important. It allows us to avoid cultural assumptions. And it also ensures that the project is working transparently because geographically remote communities need to work on the internet for it to work properly. Also, like this pencil, and looking at the age of people who are going to get this, you need to be able to use the project in different ways. Because that keeps the project modular, keeps the architecture supple, so as the needs of your users change, your project can adapt with it. So my parting thought here is that I'm going to paraphrase George Santanaio. We have lots to learn from the past, just like Ruth said earlier. And if we fail to learn the lessons of the past, then we're doomed to repeat them. Thank you very much.