| Windows/Linux | Mac OS X | Action | 
               
                  | comma | comma | Plays
                     animation backwards continuously. | 
               
                  | period | period | Plays
                     animation forwards continuously. | 
               
                  | space | space | Pauses
                     the animation. Press again to resume. | 
               
                  |  + , |  | Sets current frame the starting frame in the animation. | 
               
                  |  + . |  | Sets current frame the ending frame in the animation. | 
               
                  |  + , |  | Plays animation backwards once. | 
               
                  |  + . |  | Plays animation forward once. | 
               
                  | - | - | Slows down the playback speed of animation. | 
               
                  | + | + | Speeds up the playback speed of animation | 
               
                  | right arrow | right arrow | Proceeds to the next frame after animation is paused. | 
               
                  | left arrow | left arrow | Recedes to the previous frame after animation is paused. | 
               
                  |  + right
                     arrow |  | Proceeds to the last frame in the animation. | 
               
                  |  + left
                     arrow |  | Returns to the first frame in the animation. | 
               
                  | s |  | Cycles through animation forwards and backwards continuously.
                     (Swinging) | 
               
                  | t |  | Plays animation in real time, skipping images
                     if necessary. |