Moves the normal Drupal primary tabs into a drop-down "contextual links" menu to the right of the node title.
Contains configuration to determine which pages are excluded (such as admin*).
There are other modules that attempt to move the tabs into contextual links that mostly all use the Theme layer. This is a module-based approach. In addition, there is configuration flexibility to determine which links to pull out of the config menu as separate buttons.
For example, you can pull the "Edit" link as a separate button, with the "Gear icon" containing the rest of the tabs. You can customize which buttons are pull out of the links on a URL pattern basis. You can also rename links. For example, on a node-edit page you can pull out the normal View tab and rename it as a "Cancel" button for the edit page.
Also contains an alter hook to allow other modules to modify the links, either adding new buttons, or changing/adding the links menu.