• Free positioning of anything anywhere in painted areas on the slide, as well as in the main textblock;
• Numerous attributes to control the layout and the presentation flow, from TeX's primitive dimensions to the visibility of steps;
• Feature inheritance from global to local settings, with intermediate types;
• Basic drawing facilities to produce symbols, e.g., for list items or buttons;
• Colours, transparency, shades, and pictures;
• Navigation with links, pop-up menus, and customizable bookmarks;
• Easy switch between presentation and handout; and
• PDF transitions.

The author is Paul Isambert.