Closures considered harmful
The more closures you use in your code, the more difficult it becomes for other people to understand it, and the more memory you use (let’s not even talk about the infamous Internet Explorer memory leaks). Take a look at some hardcore closure examples and see how long it takes for you to track down which variable is declared where and how it is used.
Disclaimer: Any viewpoints and opinions expressed in this article are those of Nicholas C. Zakas and do not, in any way, reflect those of my employer, my colleagues, Wrox Publishing, O'Reilly Publishing, or anyone else. I speak only for myself, not for them.