Paint.NET is free for use in any environment, including but not necessarily limited to: personal, academic, commercial, government, business, non-profit, and for-profit. "Free" in the preceding sentence means that there is no cost or charge associated with the installation and use of Paint.NET. Donations are always appreciated, of course! http://www.getpaint.net/donate.html 

Permission is hereby granted, free of charge, to any person obtaining a copy of this software (the "Software"), to use the Software without restriction, including the rights to use, copy, publish, and distribute the Software, and to permit persons to whom the Software is furnished to do so.

You may not modify, adapt, rent, lease, loan, sell, or create derivative works based upon the Software or any part thereof. However, certain icons used in the Paint.NET user interface are from or adapted from those in the "Crystal" icon set, http://www.everaldo.com/crystal/, or the "Oxygen" icon set, http://www.oxygen-icons.org/. These icons are covered by the LGPL license, http://www.gnu.org/copyleft/lesser.html. These icons are stored as "loose" PNG image files in the Resources\en-US\ directory where Paint.NET is installed.

The above copyright notice and this permission notice shall be included in all copies of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.