frames.xsl uses frames. There are several options that you can apply:
overlay uses CSS absolute positioning to keep the navigation static on the pages (only works on recent browsers)
multiframe uses additional frames to keep the navigation static on the pages
dynamic.toc uses JavaScript to make the table of context “active” so that you can open and close the foil groups (only works on recent browsers)
active.toc uses JavaScript to keep the table of contents and the current slide in sync (only works on recent browsers)
These toc styles can be combined with overlay or multiframe