A lot of digital ink is spilled over the usability of open source software and how a lack thereof hinders the adoption of both Linux and open source software packages in general. Among the accusations frequently leveled at OSS is that UI design is an after-thought.
But, as with commercial software, there are both good and bad interface designs floating throughout the open source community. Jono DiCarlo over at Humanized, a company dedicated to creating “humane” user interfaces, recently wrote up some interesting examples of both the good and the bad in open source software design.
http://blog.wired.com/monkeybites/2007/10/making-open-sou.html