Paint.NET originated as a computer science senior design project during spring 2004 at
Washington State University. Version 1.0 consisted of 36,000 lines of code and was written in fifteen weeks.
[5] In contrast, version 3.35 has approximately 162,000 lines of code. The Paint.NET project continued over the summer and into the fall 2004 semester for both the version 1.1 and 2.0 releases.
Development continues with two developers who now work at Microsoft and worked on previous versions of Paint.NET while they were students at WSU. As of May 2006 the program had been downloaded at least 2 million times,
[6] at a rate of about 180,000 per month.
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