Per apple post - "Released today, Aperture 2.1 introduces an open plug-in architecture that lets photographers use specialized third-party imaging software from right within Aperture. In fact, customers downloading the Aperture 2.1 update will receive the new Dodge & Burn plug-in. Developed by Apple, it adds brush-based tools for dodge (lighten), burn (darken), contrast, saturation, sharpen and blur. Aperture 2 customers can download the free Aperture 2.1 Update by visiting the Aperture download site."
