The Opened Books Palette is a list of all books currently opened in Sophie. A book may be open, but its window may not be.

 * The Books should be displayed as a list.

 * A Book should be opened by dragging from the palette onto the workspace.

 * Clicking on a Book in the palette should display the corresponding Book, bring it to front and make it the current one.

[[Image(source://trunk/doc/SpecDiagrams/OpenedBooksPalette.png, 60%)]]