Paint.NET is a free photo and image editing tool designed for Windows XP or Windows 2000.
Pencil Sketch effect
In Windows Vista, the new-style Save/Open dialogs are used. Among other things, this enables Search functionality.
The View->Units, Image->Flip, Image->Rotate, and Layers->Flip submenus have been “flattened” (their commands were moved out into the View, Image, Image, and Layers menus respectively)
Renamed PdnLib.dll to PaintDotNet.Core.dll
Download size reduced by about 300 KB by using PNGOUT
Some uses of confusing “MessageBox” style dialogs have been changed to a much friendlier “TaskDialog” style interface
When changing the language, Paint.NET can now restart itself automatically
Better performance for Move Selected Pixels tool for quad-core systems. This issue is documented and explained here, http://blogs.msdn.com/rickbrew/archive/2007/03/01/paint-net-many-core-performance-scaling-analyzed.aspx
The “Clear History” button has been removed because it was not very useful
Sometimes the Colors window would get “lost” between sessions of Paint.NET
Stack-overflow crash when using certain effects, such as Gaussian Blur, on very large images with certain settings (such as a 200 pixel radius)
When cancelling the multi-image Unsaved Changes dialog, the input focus was sometimes confused
Very rare race condition in background thumbnail renderer