In a recent Adobe webinar, I used a chm file for FrameMaker 12 ExtendScript’s object model. Here is a link to the web site. Scroll to the bottom and you will see the link. After you download the chm, right+click on it and choose Properties. Click the Unblock button and you will be able to use the chm file.
The chm file has the same content as the ExtendScript Object Model Viewer, but in my opinion, is much easier to use. If you prefer HTML, there is a link to an HTML version as well.