  Increasingly, software developers are using a wide array of social
collaborative platforms for software development and learning. In this work, we
examined the similarities in developer's interests within and across GitHub and
Stack Overflow. Our study finds that developers share common interests in
GitHub and Stack Overflow, on average, 39% of the GitHub repositories and Stack
Overflow questions that a developer had participated fall in the common
interests. Also, developers do share similar interests with other developers
who co-participated activities in the two platforms. In particular, developers
who co-commit and co-pull-request same GitHub repositories and co-answer same
Stack Overflow questions, share more common interests compare to other
developers who co-participate in other platform activities.
