Goals for frameworks, languages, libraries, and tools (Goal 2)

The obvious second goal for a library has got to be that a 'library has to be simple'.

This is so important in any thing that it should almost go without saying.  However,  in the area of javascript libraries it is worth restating.  It implies both keeping a small size (for performance) and being simple to use in preexisting web pages.  Also, a library should work well with current simple technologies (that obviously have a long life span).  Lastly, you should either not have to rewrite your application to use a technology or the technology should make your application disposable (more on this later).

Being 'simple' is so important in any area of technology that I  question the longevity and disruptive capability of any technology or product that is not simple at its core.

So, goal 2 is:
A library has to be Simple