Our mission is to give readers a growing guide to the world of science ebooks. We review books about science that only exist in the digital world--Download the Universe doesn't include reviews of the automatic spin-offs of print books. But we define ebooks broadly. They may be self-published pdf manuscripts. They may be Kindle Singles about science. They can even be apps that have games embedded in them. We hope that we will eventually review new kinds of ebooks that we can't even imagine yet. And we hope that you will find Download the Universe a useful doorway into that future.