N. Megill writes "While mathematics is not "closed source" in the same way that some computer operating systems are, it can take years of hard work to acquire the background needed to understand advanced abstract mathematical proofs. This is because they are usually presented at a very high level that hides most of the detail, often making them beyond the grasp of a non-mathematician (even a very smart one such as a computer programmer). The Metamath project breaks down mathematical proofs into the finest possible level of detail and builds mathematics from the ground up. Like Linux From Scratch, it can appeal to those who like seeing things built up from first principles. Metamath does not claim to teach you mathematics, just as reading the kernel source code does not teach you how to use Linux, but there can be a certain satisfaction in just knowing it is there."