About the Documentation Viewer
Use the documentation viewer window to locate and use documentation resources for Apple developer tools and technologies.
Use the Search documentation field to find the document that best fits yours needs.
Selecting a document opens it in HTML format. The left sidebar contains the Table of Contents for your open document. To hide or show the list of the chapter and section titles for the document, click the table of contents button () to the left of the search field.
If the document is available in PDF format, you can open the PDF version by clicking the Share button () and choosing Open PDF. The share button also allows you to share documents with peers through email or Messages.
To display a navigation sidebar, click the documentation navigator button () to the left of the table of contents button. To browse the list of Apple developer documentation installed in Xcode, click the documentation library button () at the top of the sidebar. To display all of your bookmarks, click the bookmark button ().
Use the tab bar in the doc viewer to keep multiple related documents open at once. To create a tab, choose File > New > Tab (or click the Add button (+) in the tab bar).
A developer documentation set (also known as a doc set) is a standard OS X bundle that includes documentation files, binary indexes for the files and the symbols they contain, and other metadata. Xcode automatically installs the doc sets for key Apple developer libraries. Doc sets include API reference, programming guides, tutorials, technical articles, manual pages, help articles, and sample code. By default, Xcode automatically installs updates for Apple doc sets for your SDKs as they become available.