Committer
A committer is an individual who is able to modify the source code of a particular piece of open-source software. To contribute source code on most large projects, one must make modifications and then "commit" those changes to a central repository such as CVS. To have "a commit bit" on one's user account means that one is permitted to commit those changes. This dates to the use of a literal binary digit to represent yes-or-no privileges in many software systems.