I've been using paint.net for years now and it does have some pros.<p>- Sufficient even for mid-complexity art tasks<p>- Nice, simple interface<p>- Plenty of plugins<p>I don't mind the proprietary format -- since I'm usually just doing quick tasks in it, I'm either saving as jpg or png, or don't expect to need to open the pdn file at some later time or in other software.<p>However for anyone looking to start with something new, I'd really recommend using Krita or some other more recent program. Paint.net's available plugins are wildly disorganized, spread across at least one forum and hundreds of threads, often out of date or not working as intended, etc.<p>Great community and they deserve all the praise for maintaining free software for many years, but much like Gimp, it's just not the best free option available anymore.