Bonera positions itself as the wrench and screwdrivers of the rigging process rather than a full rigging system. Built by TinkerBoi, it packs a range of repetitive rigging operators, some of which are otherwise solved with simple Python scripts, into a single Blender addon.
The toolkit covers a broad set of setups. Generate Stretch Chain builds stretchy bone chains in a few clicks, Generate Eyelid handles an eyelid setup in one click, and Generate Twist Bone offers a quick twist bone setup for the forearm to prevent the candy wrap effect. Add / Apply Bone Shape applies premade widgets to bones and supports your own added shapes, Generate IK sets up IK controller and pole bones with the constraint, and Create Bone from Selected makes bones from selected vertices, edges, faces or curve points across several modes.
Bonera is split into four sections you can turn on or off in the preferences: the Bonera Toolkit (reachable via panel or the Ctrl-Shift-A menu), Pair List Renamer for renaming bones, vertex groups and shapekeys, and the Bone UI Slider Generator. Documentation and a Discord channel are available, and CG Dive has published an overview.