Paint.NET is free image and photo editing software. It features an intuitive and innovative user interface with support for layers, unlimited undo, special effects, and a wide variety of useful and powerful tools. An active and growing online community provides friendly help, tutorials, and plug-ins.
Added: "Fluid mouse input" option in Settings -> UI -> Troubleshooting. If you see major glitches while drawing, try disabling this.
Improved: Default brush size, font size, and corner radius size now scales with major DPI scaling levels (brush size of 2 at 100% scaling, brush size of 4 at 200% scaling, etc.)
Improved: Default image size now scales with major DPI scaling levels (800x600 at 100%, 1600x1200 at 200%, etc.)
Improved performance and drawing latency by removing explicit calls to System.GC.Collect() except when low memory conditions are encountered
Improved performance by greatly reducing object allocation amplification by reducing the concurrency level when using ConcurrentDictionary, and by removing WeakReference allocations in favor of direct GCHandle usage