Keywords: Tactical emphasis, short and medium term planning, area/domain/component focused, applied
Committers Groups are responsible for what goes into the project repositories (and in Galaxy everything goes into repositories, including training materials and web sites). These groups are a key component of the Galaxy Governance Model.
Each repository (repo) has it's own committers group, and each group is responsible for setting its own policies and membership. Committers have been around since the start of the project in 2005, and have been community driven since 2015.
All Committers Groups should (but don't) have clear policies for how contributors can become committers. Anyone can (and is encouraged to) contribute to any repo. Committers are the group of people who decide what gets incorporated in the repos they are responsible for. Most repos are under GalaxyProject on GitHub.
There is a loose relationship between Committers Group and Working Groups that are relevant to any given repo. Membership in working groups is wide open to anyone with the time to contribute. Committer Group membership is limited to those who have the time, and have a proven record of submitting quality contributions.