"Almost every way we make electricity today, except for the emerging renewables and nuclear, puts out CO2. And so, what we're going to have to do at a global scale, is create a new system. And so, we need energy miracles."

"For a highly motivated learner, it's not like knowledge is secret and somehow the Internet made it not secret. It just made knowledge easy to find. If you're a motivated enough learner, books are pretty good."

"The malaria parasite has been killing children and sapping the strength of whole populations for tens of thousands of years. It is impossible to calculate the harm malaria has done to the world."

"The thing about HD-DVD that is attractive to Microsoft is that it's very pro-consumer in letting you copy all movies up onto the hard disk."

"What's amazing is, if young people understood how doing well in school makes the rest of their life so much interesting, they would be more motivated. It's so far away in time that they can't appreciate what it means for their whole life."

"The advance of technology is based on making it fit in so that you don't really even notice it, so it's part of everyday life."

"Security is, I would say, our top priority because for all the exciting things you will be able to do with computers - organizing your lives, staying in touch with people, being creative - if we don't solve these security problems, then people will hold back."

"The way to be successful in the software world is to come up with breakthrough software, and so whether it's Microsoft Office or Windows, its pushing that forward. New ideas, surprising the marketplace, so good engineering and good business are one in the same."

"If I'd had some set idea of a finish line, don't you think I would have crossed it years ago?"

"I went to a public school through sixth grade, and being good at tests wasn't cool."

"To create a new standard, it takes something that's not just a little bit different; it takes something that's really new and really captures people's imagination, and the Macintosh, of all the machines I've ever seen, is the only one that meets that standard."

"Just in terms of allocation of time resources, religion is not very efficient. There's a lot more I could be doing on a Sunday morning."

"There are people who don't like capitalism, and people who don't like PCs. But there's no-one who likes the PC who doesn't like Microsoft."

"This whole phenomenon of the computer in a library is an amazing thing."

"Contrary to popular belief, I don't spend a whole lot of time following soccer. But as I have traveled around the world to better understand global development and health, I've learned that soccer is truly universal. No matter where I go, that's what kids are playing. That's what people are talking about."

"The common thread for everything I do is this idea of a Web-services architecture. What does that mean? It means taking components of software and systems and having them be self-describing, so that you can aim them, ask them what their capabilities are, and communicate with them using a standard protocol."

"If you can't make it good, at least make it look good."

"The Gates Foundation has learned that two questions can predict how much kids learn: 'Does your teacher use class time well?' and, 'When you're confused, does your teacher help you get straightened out?'"

"If GM had kept up with technology like the computer industry has, we would all be driving $25 cars that got 1000 MPG."

"Life is not divided into semesters. You don't get summers off and very few employers are interested in helping you find yourself."

"If you're low-income in the United States, you have a higher chance of going to jail than you do of getting a four-year degree. And that doesn't seem entirely fair."

"DNA is like a computer program but far, far more advanced than any software ever created."

"Microsoft is not about greed. It's about innovation and fairness."

"At Microsoft there are lots of brilliant ideas but the image is that they all come from the top - I'm afraid that's not quite right."

"I'm a great believer that any tool that enhances communication has profound effects in terms of how people can learn from each other, and how they can achieve the kind of freedoms that they're interested in."

"This is a fantastic time to be entering the business world, because business is going to change more in the next 10 years than it has in the last 50."

"Drones overall will be more impactful than I think people recognize, in positive ways to help society."

"The intersection of law, politics, and technology is going to force a lot of good thinking."

"When you have money in hand,only you forget who are you .But when you do not have any money in your hand,the whole world forget who you are.It's life."

"The moral systems of religion, I think, are super important."

"People everywhere love Windows."

"Well private money can take risks in a way that government money often isn't willing to."

"Eventually we'll be able to sequence the human genome and replicate how nature did intelligence in a carbon-based system."

"If you have 50 different plug types, appliances wouldn't be available and would be very expensive. But once an electric outlet becomes standardized, many companies can design appliances, and competition ensues, creating variety and better prices for consumers."

"We should all grow our own food and do our own waste processing, we really should."

"You may have heard of Black Friday and Cyber Monday. There's another day you might want to know about: Giving Tuesday. The idea is pretty straightforward. On the Tuesday after Thanksgiving, shoppers take a break from their gift-buying and donate what they can to charity."

"We've got to put a lot of money into changing behavior."

"OK, I have a nickname. My family calls me 'Trey' because I'm William the third. My dad has the same name, which is always confusing because my dad is well known, and I'm also known."

"People should just buy a CD and rip it. You are legal then."

"Life is not fair; get used to it."

"Some people may call me a nerd. I claim the label with pride."

"The typical project design time for a large company like IBM - and they keep track of this - is a little over four years."

"We are not even close to finishing the basic dream of what the PC can be."

"Software is a great combination between artistry and engineering."

"People always fear change. People feared electricity when it was invented, didn't they? People feared coal, they feared gas-powered engines... There will always be ignorance, and ignorance leads to fear. But with time, people will come to accept their silicon masters."

"My son likes to go see mines and electric plants, or the Large Hadron Collider, and we've had a chance to see a lot of interesting stuff."

"Now, we put out a lot of carbon dioxide every year, over 26 billion tons. For each American, it's about 20 tons. For people in poor countries, it's less than one ton. It's an average of about five tons for everyone on the planet. And, somehow, we have to make changes that will bring that down to zero."

"In business, the idea of measuring what you are doing, picking the measurements that count like customer satisfaction and performance... you thrive on that."

"By the time we see that climate change is really bad, your ability to fix it is extremely limited... The carbon gets up there, but the heating effect is delayed. And then the effect of that heat on the species and ecosystem is delayed. That means that even when you turn virtuous, things are actually going to get worse for quite a while."

"Innovations that are guided by smallholder farmers, adapted to local circumstances, and sustainable for the economy and environment will be necessary to ensure food security in the future."