I have a JavaScript library which is well-annotated to produce documentation with JSDuck. I think that such annotations are sufficient to provide good IntelliSense for my library. Also, they are pretty standard, because JSDuck syntax is designed to be an extension of popular Google Closure Compiler syntax. But it seems like there is no IDE which makes use of code annotations to provide IntelliSense. There are many "smart" engines which try to suggest the types of variables but there is no "solid" engine which reads annotations to even determine which classes my library has.
If it is useful, here are links to my library and its documentation generated by JSDuck.
