The new things in 2.1:

   - added playing of WAVE sounds - resources 860,861,870,...
   - added playing of any MCI videos (e.g avi) in the SVGA version
   - changed the title picture
   - added the 'save layout' feature which was removed in 2.0
   - added some image displaying options - aspect ratio, fit in
     the window, etc.
   - added 'About' box and placed the options in the windows menus

The new things in 2.1b:
   
   - fixed bug which appeared in 2.1 with the improper image update