Short list of what's new in version 9.1 :

• GPU accelerated ray tracing: Puppy Ray GPU
  
• New free transform tool
  
• New options for alpha channel selections
• New line, rectangle, and circle options
• New crop tool
• New interactive font picker
• New icon set, color schemes, and light on dark color schemes
• More options available on the context strip for quicker access
• New fill panel
• New options for plasma nois, including seamless mode and more
• Speed improvements
• GUI improvements and bug fixes

  Note to Windows XP users:  The GPU support is not available with Windows XP. It is time to move to Windows 7 or 8. If you want to use the CPU version of Puppy Ray, look here for a patched dll needed under XP.