Have a look at a preview of the upcoming Zoo Tools Pro v2.
Zoo Tools 2 is a modular framework for Maya that would be useful for artists and TDs/developers. You can either just use it or add your own tools if you’re a coder.
The developers pointed out that toolsets are only one aspect of Zoo Tools 2. The update will also bring new auto-rigger, browsers for image-based tools, preferences windows, trigger marking menus, hotkeys and more.
You can learn more about the toolkit here.