Is there a single window application that can read CHM, PDF and DJVU? I discovered recently that Preview.app can be configured so that it's using only one window for all documents, instead of one window per document. The drawback is that you can only read one document at a time, but I'm fine with this limitation.

I often have 5 to 10 text documents (CHM, PDF and DJVU) open at the same time, and I hate to have each document eat space in the Dock.

I'm looking for a way to gather all the text documents in one application, with only one window. Is there a software which handles the three formats I mentioned, and limits itself to one window ?
Firefox can with plugins. Like most browsers, Firefox already has a pdf viewer built in, but there are plugins available for chm viewing, as well as for djvu viewing. With tabbed browsing, you can have many documents open in a single window.