You also have the (probably outdated) actual w3c javadoc [1] and GWT docs that closely emulate the dom [2]. I believe yours is a tad bit more complete (and not all_java related), but less documented.
The link is _not_ java api. It is javascript dom api available in the browser. But, the API is documented in javadoc style. Ofcourse, w3c has more detailed documentation. But it is hard to refer quickly. javadoc style api is very easy to navigate and refer.