Ray Gun - The Number System in JavaScript

NAN is the most important of the things that you mentioned. It's the most you're most likely to wreck your head against it. Have you ever wondered if you could be offering a faster, less buggy experience for your customers? The only way you're going to know that is by actually running it on production. Greping through logs is no fun. So go check out Ray Gun. They are definitely going to help you out.