Changes in Paint.NET version 3.5.3 Beta, build 3685:
Fixed a mismatched file name issue with the File->Save dialog in Win7/Vista, as originally reported here. This issue is still present on XP but cannot be fixed.
Fixed DirectDraw Surface (.DDS) file format support for CPUs which do not have SSE2 (Pentium III, Athlon XP).
Fixed some crashes which were actually supposed to be “out of memory” error dialogs (without a crash!).
Fixed a race condition with the New Image, Resize, and Canvas Size dialogs. If you typed very very fast you could get it to crash by typing a negative value and immediately pressing OK or Enter..
Removed splash screen.

>> Paint.NET website
>> Download Paint.NET 3.5.3 beta build 3865

Changes/fixes since v3.5:
New: For Windows 7, added taskbar progress reporting for long running operations (effects, adjustments, Image->Resize, save, install)
Made some corrections to the French translation
Running setup with /auto will no longer launch Paint.NET when it’s done
Fixed an issue where Paste into New Image would refuse an image on the clipboard, even if regular Paste would take it
Fixed a race condition with Edit->Paste and Image->Resize whereby it would take up 100% CPU and take between 1 minute to 1 hour to finish
Fixed an issues with Copy/Paste where it would leave an extra line of transparent pixels on the left, top, right, and/or bottom edges
Fixed lag with the paintbrush tool that was being seen on some systems
Fixed some issues with the paintbrush and eraser tool being misaligned when zoomed in
Fixed a crash that would happen at (seemingly) random times, such as after drawing with the paintbrush tool, on some systems
Fixed a minor and obscure rendering glitch with the Move Selected Pixels tool
Fixed an issue with glass over Remote Desktop or Windows 7 Virtual PC
Fixed a minor glitch whereby the “Unsaved Changes” confirmation dialog could never finish rendering the image thumbnail if one of the Move tools was active

>> Paint.NET website
>> Download Paint.NET 3.5.1

Changes since version 3.36:
New: Refreshed user interface with new icons and visual styling. On Windows 7 and Vista, it is enhanced for Aero and “glass”.
New effect: Blurs -> Surface Blur, by Ed Harvey
New effect: Distort -> Dents, by Ed Harvey
New effect: Distort -> Crystalize, by Ed Harvey
New: Russian translation.
Performance and memory usage have been extensively optimized throughout the entire program.
.NET Framework 3.5 SP1 is now required, which has many built-in performance improvements.
Disk space usage has been reduced by about 12MB by using NTFS compression on installation files related to staging (.MSI) and diagnostics (.PDB).
Compression for .PDN images has been improved.
Effect dialog responsiveness has been improved.
Images open much faster, especially on single CPU systems.
Startup performance on most systems will be better by about 20%.
Memory usage has been reduced when more than one image is open.
Rendering quality has been greatly improved when zoomed in.
The selection outline is no longer animated. Instead of “dancing ants”, a context-sensitive “XOR” stipple pattern is drawn. This has allowed for improved performance and lowered CPU consumption (and longer battery life).
The font manager for the Text tool has been completely rewritten, which fixes many problems seen with crashes and missing fonts.
On Windows XP, the Text tool has improved reliability and font selection (it uses GDI instead of GDI+).
On Windows 7, the Text tool will use DirectWrite (instead of GDI) which gives better performance and greatly improved quality. On Windows Vista, you may install DirectX 11 to enable this feature; otherwise GDI will be used.
The toolbar font list has improved usability, rendering quality, and significantly improved performance.
The toolbar font list no longer requires an application restart to recognize newly installed fonts.
When many fonts are installed, both memory usage and startup performance have been greatly improved.
It is now drastically easier to move a very small selection.
All installation prerequisites are now installed automatically, such as .NET and Windows Installer.
Updates are now downloaded in the background, and installed after you exit the application. In previous versions, this was a foreground task and you could not use Paint.NET while the update was downloaded.
Added a “Utilities” menu. Updates, Languages, and Plugin Errors have been moved there.
Added a “Manage Fonts” command to the Utilities menu. This will launch the built-in Windows font control panel.
Clicking the middle mouse button on an image thumbnail will now close the image.
Improved the Unfocus effect.
The DirectDraw Surface (.DDS) file type now allows you to select the resampling algorithm for auto-generated mip-maps.
A processor that supports SSE is now required (almost all CPUs purchased this decade satisfy this).
Fixed an issue with Gaussian Blur and its treatment of alpha values.
Fixed a crash with the “Units” selector in the toolbar.
Fixed a crash due to an overflow that prevented very large images from working (64-bit only).
Fixed many other miscellaneous glitches and crashes.
The Korean translation has been removed. Sadly, we were unable to find the resources to complete this.

>> Paint.NET website
>> Download Paint.NET 3.5

Changes/fixes since version 3.5 Beta 1:

* The menu bar was rendering incorrectly for certain themes (Windows 7 / Vista).
* Some items were not showing up in the ‘Recent Items’ jump list (Windows 7).
* Clicking on the canvas straight from the menu would cause the paintbrush to draw a long streak.
* Copy+Paste would sometimes miss a pixel edge on the right/bottom sides, when using Fixed Ratio / Fixed Size modes.
* Fixed a crash when moving pixels off-canvas, switching tools, then trying to move the pixels back onto the canvas.
* Fixed some messed up rendering for IndirectUI effect dialogs (Windows XP).
* Performance is improved when switching between images that have lots of layers.
* Aero ‘snap’ wasn’t working when dragging part of the glassy area of the toolbar (Windows 7).
* Added a new menu item, Window -> Glass Dialog Buttons. You can use this to disable the “glass footers” for dialogs (Windows 7 / Vista).
* Glass Dialog Buttons are now disabled when font smoothing is disabled.
* If an e-mail program isn’t installed, the error message for Help->Send Feedback is more informative.
* “Centimeters” was being truncated in the toolbar.
* The shape tools were not using pixel snapping.
* Layer names with ampersands were not showing up correctly.
* Updated the internal list of incompatible and unstable plugins, which are then blocked from loading.
* Fixed a crash with the Rectangle Select tool if “Fixed Size” mode was used and negative numbers were entered.
* Fixed an access violation due to a race condition in finalizing effect rendering versus un-write protecting the layer’s pixels.
* Fixed an access violation in the renderer for the background transparency “checkers”.
* Fixed a crash when you would resize a selection to 0-width and/or 0-height, then expand it.
* Fixed a crash due to an overflow that prevented very large images from working (64-bit only).
* Fixed a crash with scanning/printing.
* Fixed the status bar’s progress bar showing up and doing nothing for codecs that don’t report saving progress, such as JPEG.
* Fixed a major issue with the readability of the “update is available” dialog in any non-English language.
* Fixed a crash with the Zoom tool.
* Fixed some really weird scroll-flickering with the Text tool.

>> Paint.NET website
>> Download Paint.NET 3.5 beta 2 build 3561

>> Download Paint.NET 3.5 alpha

New:

* Posterize adjustment
* Intersect selection editing mode.
* When holding Ctrl or Alt for a selection tool, the cursor now has a plus or minus indicator.

Improved:

* Dramatically improved selection editing performance for the Add and Subtract modes (and also for Intersect). The performance used to be dependent on image size, and thus was often unusable on images larger than 1024×768 pixels. It is now dependent only on selection complexity (number of polygon edges) — the improvement is generally between 3x and 1000x.

Changed:

* The canvas background is now a solid color instead of a gradient. The gradient was causing certain tone misjudgments related to bright versus dark colors.
* Shortcut key for Sepia is now Ctrl+Shift+E. The shortcut for Posterize is now Ctrl+Shift+P.
* Hotkeys for selection modes are now Left click for Replace, Control+Left click for Add (union), Alt+Left click for Subtract (difference), Ctrl+Left click for Intersect, and Ctrl+Right click for Invert (xor).
* When using a selection mode other than “replace”, it will now draw the selection outline so that you can see both the original and resulting selection areas. Before, it would only draw the resulting selection area outline, which made modes such as Intersect hard to use.

Fixed:

* The Resize dialog had some rounding errors with the “Maintain aspect ratio” feature, which caused a few discrepancies and even a spurious “out of memory” error.
* Some quirks with the Color Wheel control for IndirectUI-based effect plugins.
* Several miscellaneous and rare crashes.
* The installer would display a bizarre error if a “blank” install folder was attempted.
* The installer now only accepts absolute path locations, instead of relative ones. This fixes an ambiguity between where Paint.NET believes it is installing itself to, and the directory that Windows Installer actually uses.
* Sometimes pasting would result in a crash when certain types of malfored data were on the clipboard.
* It was possible to get around some of the protections imposed by the IndirectUI system. This was causing instability with some effect plugins such as “Fern Fractal”.
* There were some issues with the implementation of “linked” sliders for effects based on IndirectUI.

>> Paint.NET website
>> Download Paint.NET 3.35

This release adds an Italian translation, a new “Fragment Blur” effect, and the ability to save PNG images at 8- and 24-bit color depths. For developers, the IndirectUI system has some new controls, some new constraint rules, and can now be used for file type plugins.

* New: Italian translation.
* New: Ability to save PNG’s at 8- and 24-bit color depths.
* New: Ability to save BMP’s at 8-bit color depth.
* New: “Auto-detect” bit-depth option for PNG, BMP, and TGA file types. It will analyze the image and determine the lowest bit-depth that can still save the image without quality loss.
* New: “Fragment” blur effect, by Ed Harvey

>> Paint.NET website
>> Download Paint.NET 3.30