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. in contrast, version 3.35 has approximately 162,000 lines of code. the paint.net project continued over the summer and into the autumn 2004 semester for both the version 1.1 and 2.0 releases.