Split View in Cocoa Apps

Does anybody know of any XCode extensions or ways to create the Split View based application seen in Cocoa Touch in C开发者_如何学运维ocoa for use in a Mac application?

Examples I've seen are "Reeder for mac" and the latest Twitter Application in the App Store.

Any help is greatly appreciated, thanks

Cocoa has an NSSplitView class which can be used in Interface Builder, and you can always create custom split views or use open source ones such as RBSplitView or the one available in BWToolkit.

What additional functionality are you looking for that isn't provided by the already-available NSSplitView?

Reeder for Mac seems to use a simple NSSplitView with 3 subviews. (To create a split view with 3 views, drag the usual NSSplitView into a window or view in InterfaceBuilder, then drag an additional NSView into the NSSplitView in the "Outline Mode" of your IB document's window.)