This talk focusses on a central difference between UX designers and Open Source developers: The ideas of what a "good" user is and one should relate to them. Given their different cultures and histories, both have come to different conclusions: The ideal user for open source projects is a programmer themselves and thus similar to the people already working on the software – whereas for UX designers, the users are seen as unlike designers nor programmers and understanding them and transporting that understanding in the project is seen as a major and difficult task. Based on these differences, the suggestion is not to educate one profession to act like the other. Instead, I look at existing modes of cross-professional collaboration assuming that the strenght of working together are also the very different skills and assumptions that designers and developers bring to the project.