Contextual Administration is an administration tool based on CTools Page Manager module. It allows for the deployment of custom administrative pages through a typical database driven mechanism or can take advantage of the typical page_manager exports through custom modules + exports or features module.
My specific use case in creating context_admin to begin with was to give site administrators who don't have the programming know-how the ability to add traditionally developer style administration links to their site in an ad-hoc fashion. The best example of this would be adding "create new node X" or "administer node X" links to views of "node X", however once the tool was created, it became obvious rather quickly that we could do much more.
By default Contextual Administration comes with the ability to add nodes of any type, edit/add/list taxonomy terms, edit vocabularies, and add users. An additional module provides Views Bulk Operations specific plugins for node management. The primary difference between these features and core's ability to do these things is that context_admin is creating new pages and controls access to these pages through page_manager's access plugins. In this manner web administrators can give access to users to do particular tasks from particular pages w/o giving them the sitewide ability to perform the same functions. A good example would be that the "administer taxonomy" permission wouldn't necessarily be required to utilize the various taxonomy capabilities that context_admin has by default, as this is all controlled by the page's page_manager access handler(s). This ability can be coupled with custom code, or custom context_admin plugins to result in "sub users", "sub nodes" or any variety of other management tools.
This module depends on page_manager which is part of the ctools module.