I'd suggest it might be more worthwhile thinking in terms of development teams and UX teams.
I think the appeal of working on an OSS is that a developer gets to hone their skills and work collaboratively. It's a way to contribute (give back), to gain experience and to gain kudos.
I don't think the same collaborative aspect works as easily for design - because design problems are perhaps less easily worked on iteratively as a group.
UX, as a discipline, involves problems which can be solved collaboratively - and lends itself to team work. Design that's born from UX research tends to solve problems which have been more clearly defined from the outset.
I think the appeal of working on an OSS is that a developer gets to hone their skills and work collaboratively. It's a way to contribute (give back), to gain experience and to gain kudos.
I don't think the same collaborative aspect works as easily for design - because design problems are perhaps less easily worked on iteratively as a group.
UX, as a discipline, involves problems which can be solved collaboratively - and lends itself to team work. Design that's born from UX research tends to solve problems which have been more clearly defined from the outset.