Open source software is a really big thing and I'm a great fan of it. I like to use third party controls, I like to contribute pushing other devs software forward and I feel a need to give something back by extracting the one or another line of code of private projects encapsulating in own controls.

CCNNavigationController

A Navigation Controller for macOS that acts mostly like the counterpart on iOS - UINavigationController, using the excact method naming (with some additions).

CCNStatusItem

CCNStatusItem is a subclass of NSObject acting as a custom NSStatusItem. Running on Yosemite it has full support for the class NSStatusBarButton which is provided by NSStatusItem via the button property. You can use custom views or just an image.
When you click on an CCNStatusItem it presents an animated popover with your viewcontroller as content. There are several animation and configuration options available.

CCNPreferencesWindowController

CCNPreferencesWindowController is an Objective-C subclass of NSWindowController that automatically manages your custom view controllers for handling app preferences.

CCNLaunchAtLoginItem

CCNLaunchAtLoginItem is a Objective-C class that encapsulates the functionality for launching a Mac application automatically on login, presented in a very simple interface.
Note: This control ONLY works in non-sandboxed apps! Using it in software for the Mac App Store will end up in rejection.

CNUserNotification

CNUserNotification is a kind of proxy to give MacOS Lion 10.7 „the same‟ support for user notifications like macOS Mountain Lion 10.8 does. Benefits are also a bit more flexibility since you are able to define a custom banner image or variable dismiss delay times. CNUserNotification uses a fake notification center that runs just per application. The class design and all method signatures are similar to their counterparts of NSUserNotification.

CNGridView

CNGridView is a (wanna be) replacement for NSCollectionView. It has full delegate and dataSource support with method calls like known from NSTableView/UITableView.
Note: At the moment it is on hold - aka not actively under development.

CNBackstageController

CNBackstageController is an derivative of NSWindowController and a special impelementation to show you the content you would like to see. The goal of CNBackstageController is to provide the developer a slightly different interface for presenting an application.

It mimics the behavior you’ve just seen in Notification Center of Mountain Lion. Instead of showing a normal window and menu bar an application build with CNBackstageController offer you a behind the Finder-like desktop and will be shown with smooth animations. The common use is an application nested as a statusbar item that is not visible in the Dock.

Note: This was a proof of concept and never found a place in a real application. Therefore it's no longer supported and development has been discontinued!