  For teams using distributed version control systems, the right collaborative
development workflows can help maintaining the long-term quality of project
repositories and improving work efficiency. Despite the fact that the workflows
are important, empirical evidence on how they are used and what impact they
make on the project repositories is scarce. Most suggestions on the use of
workflows are merely expert opinions. Often, there is only some anecdotal
evidence that underpins those advices. As a result, we do not know what
workflows are used, how the developers are using them, and what impact do they
have on the project repositories. This work investigates the various
collaborative development workflows in eight major open-source projects,
identifies and analyses the workflows together with the structures of their
project repositories, discusses their similarities and differences, and lays
out the future works.
