Best web UI to navigate through a treee like structure


In my web application I have a tree like structure very similar to folders and files. I need help in the UI design of a page which helps users navigate through the structure. Users will be allowed to move entities(files) among various groups(folders). At a glance anyone would think of two-panel pattern and a tree view like Windows explorer. But I cannot provide users drag drop facility to our design restrictions. Also a new requirement states that the users should be able to bulk move entities(selecting more than one item at a time) among groups. It would be too cool if you can give your valuable directions. I am looking for an appealing and innovative UI which will ease the users doing their tasks