initially, paint.net was released under a modified version of the mit license, with the exclusion of the installer, text, and graphics. it was completely open-source, but because breaches of license, all resource files (such as interface text and icons) were released under a non-free creative commons license forbidding modification, and the installer was made closed-source. version 3.36 was initially released as partial open-source, but brewster later took down the source code, citing problems with plagiarism. in version 3.5, paint.net became proprietary software. users are now prohibited from modifying it.