Bunyan is a work-in-progress tool for guiding and facilitating CHANGELOG generation from git log output. Lots of tools exist that do this in an automatic way: however, Bunyan does not want to simply generate a changelog for you; instead, it's a tool for walking git log output and asking you to categorize or ignore each commit, then rearranging and formatting those commit messages in a way that is more amenable to reading by an end-user.