6. Remain flexible if I want to modify the behavior without changing your source code, this is easy? If it's not easy enough, make it easier.
7. Manage memory you need to do your best to worry about memory leaks.
8. Eliminate browser sniffing looks like browser vendors will always compete by adding new features;- As a library developer, you need to keep abreast of the latest trends. Browsing the Ajaxian once in a while is not enough, you have to read every blog post to find the next hack in a slave-like manner. Browsers can be addicted to sniffing.
10. Rules tenth good ol ' tenth rule (seems to be a colloquial usage, do not know how to translate well). You can always rely on rule tenth. This is: Keep predictable. I should have guessed what your method was for. If I don't know the name of a certain method, I should be able to guess it.
11. Additional Rules
Documents that are annoying but absolutely necessary to do.
The more namespaces you use, the harder it is for me to remember, just like your phone number.
Remember: There may be millions of people who will execute your code.