A great little program but was always a little sluggish on slower computers. I've noticed a huge difference in speed and performance compared to version 3.3x. Only for the daring, but so far I haven't run into any show stopping bugs for me. I even have it loaded up in my XP Mode VM so I can scan expenses with the old Epson USB scanner on my 64-bit host.
Changes since version 3.36:
Requires and uses! .NET Framework 3.5 SP1
Significant improvements to the installer. Prerequisites are now handled in a much more user-friendly fashion.
The auto-updater can now download in the background, and then install the update after you've exited Paint.NET. Compare this to v3.36 and earlier that jump in your face and require the download and installation to happen right now, and block you from using the program until it's done!
New effects: Blurs -> Surface Blur, Distort -> Dents, Distort -> Crystalize - by Ed Harvey
The responsiveness of effect dialogs has been greatly improved.
When zoomed-in, the rendering quality has been substantially improved.
When zoomed in, it is now much easier to correctly resize or move a selection.
Improved performance when opening multiple images, especially for systems with only 1 processor.
Memory usage has been greatly reduces when more than one image is open.
The selection outline is no longer animated, which substantially reduces CPU usage. It also uses XOR blending.
The middle mouse button can now be used to close an image tab.
Improved the Unfocus effect.
Fixed an issue with Gaussian Blur and its treatment of alpha values.
Fixed a crash with the "Units" selector in the toolbar area.
Added a "Utilities" menu, and moved the following menu items there: Check for Updates, Language chooser, and View Plugin Load Errors. For the alpha release, there are also menu items for "Force Crash" and "Perform Full GC" (you'll know what that means if you're a developer -- Otherwise it isn't interesting).
Installer now has a "Start Paint.NET" checkbox at the end. (On Vista and Win7 with UAC enabled, it will correctly start Paint.NET at non-elevated privilege.)
Renamed "Grid" to "Pixel Grid", to more accurately describe its functionality.
The DirectDraw Surface (.DDS) file type now allows you to select the resampling algorithm for auto-generated mip-maps.
Effect plugins now have access to a "Services" property which allows them to properly access certain internal Paint.NET functionality.
Fixed some very small memory leaks when opening many images.
Russian translation.
A processor that supports SSE is now required (almost all CPU's purchased this decade satisfy this).
You can read about it more and download it from
here.