  Modern communication platforms such as Gitter and Slack play an increasingly
critical role in supporting software teamwork, especially in open source
development.Conversations on such platforms often contain intensive, valuable
information that may be used for better understanding OSS developer
communication and collaboration. However, little work has been done in this
regard. To bridge the gap, this paper reports a first comprehensive empirical
study on developers' live chat, investigating when they interact, what
community structures look like, which topics are discussed, and how they
interact. We manually analyze 749 dialogs in the first phase, followed by an
automated analysis of over 173K dialogs in the second phase. We find that
developers tend to converse more often on weekdays, especially on Wednesdays
and Thursdays (UTC), that there are three common community structures observed,
that developers tend to discuss topics such as API usages and errors, and that
six dialog interaction patterns are identified in the live chat communities.
Based on the findings, we provide recommendations for individual developers and
OSS communities, highlight desired features for platform vendors, and shed
light on future research directions. We believe that the findings and insights
will enable a better understanding of developers' live chat, pave the way for
other researchers, as well as a better utilization and mining of knowledge
embedded in the massive chat history.
