Paint.NET  4.0 Beta 3
Paint.NET is free image and photo manipulation application for the Windows platform. Every feature of Paint.NET, including the user interface, was designed to be immediately intuitive and easy to learn without assistance.
Key Features Include:
- Special effects tools include: blurring, sharpening, red-eye removal, distortion, noise and embossing.
- 3D Rotate/Zoom effects make it very easy to add perspective and tilting.
- Image manipulation tools include: brightness, contrast, hue, saturation, curves, and levels. You can also convert an image to black and white, or sepia.
In order to navigate multiple images easily, Paint.NET uses a tabbed document interface. The tabs display a live thumbnail of the image instead of a text description.
Paint.NET uses a layers system to form the basis for rich image composition. Layers are likened to a stack of transparency slides that, when viewed together at the same time, form an image.