On the characteristic lack of usability in open source projects, and why. "The distributed, collaborative nature of open source software works for developer-level software, but works against user-level software. Imagine a motion picture produced like a large open source project. Different scenes written and directed by different people, spread across the world. Editing decisions forged by group consensus on mailing lists. The result would be unfocused, incoherent, and unenjoyable."
Cabel Sasser: Coda Toolbar and the Three Pixel Conundrum
Panic's graphic designer worked out a new design for the Coda toolbar that required the team to write a custom UI widget. Going the extra mile inspired Apple to do the same for Leopard.