Most notable of Git 2.54 is the new, experimental git history command. The git history usage is an easier approach for rewriting some elements of a repository's history that is less complex than existing tooling. Git history currently supports "reword" and "split" sub-commands. Using git history reword [commit] opens your editor and allows rewiring in place the specific commit's message and will then update any branches too that descend from that commit. The git history split [commit] command can be used to interactively split a commit into two by selecting the hunks that should be carved out into a new parent commit.
Git 2.54 also now provides a new way to define hooks in your configuration file that works for commands outside of the current Git/hook directory. Geometric repacking during maintenance by default is now enabled as is a variety of other smaller improvements.
More details on the Git 2.54 changes can be found via the GitHub Blog and Git 2.54 release announcement .