A framework for developing interfaces on the Mac.
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This fork of TwUI is feature-frozen. Our feature work is focusing on Rebel instead.

You might be able to find a more active fork of TwUI by checking out the network graph.


TwUI is a hardware accelerated UI framework for Mac, inspired by UIKit. It enables:

  • GPU accelerated rendering backed by CoreAnimation
  • Simple model/view/controller development familiar to iOS developers

It differs from UIKit in a few ways:

  • Simplified table view cells
  • Block-based layout and drawRect
  • A consistent coordinate system (bottom left origin)
  • Sub-pixel text rendering


To use the current development version, include all the files in your project and import TUIKit.h. Set your target to link to the ApplicationServices and QuartzCore frameworks.


Your TUIView-based view hierarchy is hosted inside an TUINSView, which is the bridge between AppKit and TwUI. You may set a TUINSView as the content view of your window, if you'd like to build your whole UI with TwUI. Or you may opt to have a few smaller TUINSViews, using TwUI just where it makes sense and continue to use AppKit everywhere else.

You can also add NSViews to a TwUI hierarchy using TUIViewNSViewContainer, which bridges back into AppKit from TwUI.

Example Project

An included example project shows off the basic construction of a pure TwUI-based app. A TUINSView is added as the content view of the window, and some TUIView-based views are hosted in that. Within the table view cells, some NSTextFields are also added using TUIViewNSViewContainer. It includes a table view and a tab bar (which is a good example of how you might build your own custom controls).


TwUI is currently shipping in Twitter for Mac and GitHub for Mac, in use 24/7 by many, many users, and has proven itself very stable.

This project follows the SemVer standard. The API may change in backwards-incompatible ways between major releases.

The goal of TwUI is to build a high-quality UI framework designed specifically for the Mac. Much inspiration comes from UIKit, but diverging to try new things (i.e. block-based layout and drawRect), and optimizing for Mac-specific interactions is encouraged.


TwUI has a mailing list, subscribe by sending an email to twui@librelist.com.

Copyright and License

Copyright 2011 Twitter, Inc.

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this work except in compliance with the License. You may obtain a copy of the License in the LICENSE file, or at:


Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.