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Choosing a UNIX Graphical Environment

Many UNIX applications are designed using high-level widget toolkits such as Tcl/Tk, Motif (or OpenMotif or Lesstif), and Qt. These environments work well across many platforms. However, that cross-platform nature comes with a price in flexibility. In essence, to be cross-platform, they can only support capabilities that are generic to all of the potential operating environments, and as such, they tend to provide only the lowest common denominator in terms of functionality.

Such toolkits are often weak in areas such as performance and flexibility, and many do not allow precise control over how GUI elements are laid out.

If they provide everything you need, then they are good choices. Otherwise, a more flexible alternative such as raw Xlib programming, or a more Mac-tuned alternative such as Carbon or Cocoa may be more appropriate.

Other UNIX solutions exist for more extreme cross-platform environments. One example is MicroWindows, which is designed to allow ease of code sharing between X11 and Windows by implementing a subset of the Win32 graphics APIs on X11. Because this is really just an X11 application, it should be possible to use it on Mac OS X. However, due to the amount of abstraction involved, such a solution will not perform as well as a native application.

If you are trying to design an application for such an environment, it is generally better to rearchitect your code to have multiple front-ends—one for Windows, one for Mac OS X, and one for UNIX (X11). See “(Re)designing for Portability” for more information on creating a graphics abstraction layer.

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