The Core Graphics framework is based on the Quartz advanced drawing engine. It provides low-level, lightweight 2D rendering with unmatched output fidelity. You use this framework to handle path-based drawing, transformations, color management, offscreen rendering, patterns, gradients and shadings, image data management, image creation, and image masking, as well as PDF document creation, display, and parsing.

Core Video provides a pipeline model for digital video. Partitioning the processing into discrete steps makes it simpler for developers to access and manipulate individual frames without having to worry about translating between data types (QuickTime, OpenGL, and so on) or display synchronization issues. Applications that do not need to manipulate individual video frames should never need to use Core Video directly.

The Image I/O programming interface framework allows applications to read and write most image file formats. This framework offers high efficiency, color management, and access to image metadata.

ARC and GCD Compatible Reachability Class for iOS and OS X. Drop in replacement for Apple Reachability.

Secure the data your app manages. Protect information and control access to your app.

This collection of documents describes the programming interfaces of the System Configuration framework. The System Configuration framework provides functions that determine the reachability of target hosts in both a synchronous and an asynchronous manner. It also provides error detection facilities.

The Accounts framework provides access to user accounts stored in the Accounts database. An account stores the login credentials of a particular service, such as Twitter, that can be used as authentication for the service. By implementing the Accounts framework into your app, you do not need to be responsible for storing account logins yourself. Instead, the user can grant access for your app to use their account login credentials, bypassing the need to type their username and password. If no account for a particular service exists in the user’s Accounts database, you can let them create and save an account from within your app.