More often than not, programming is collaborative. Whether this collaboration is implicit (such as referencing a post on StackOverflow) or explicit (such as merging into a multi-user codebase), effective communication tools can help programmers write better code. In this talk, I will describe work that our research group has done to (1) study how programmers communicate when working in teams and (2) build systems to improve communication between programmers. I will focus particularly on our work with data scientists and mixed-ability programming teams.