• Because it serves as one of the core components of the popular GNOME desktop for Linux, GTK+ development should be strong for the foreseeable future. The Ruby/GTK extension is likewise under ongoing development and already exposes most or all of the GTK+ functionality.

• One potential source of problems for GTK+ (and hence Ruby/GTK) is the weakness of the Windows port of GTK+, which typically lags behind the main X Window version. It is likely, however, that these problems will be sorted out at some point with the redesigned GTK+ 2.0.

Using the FOX Toolkit

• FOX provides an excellent cross-platform GUI solution, and unlike GTK+, it works very well out of the box on both Linux and Windows. In addition to its extensive collection of modern widgets, FOX offers built-in support for drag-and-drop, OpenGL, and a wide variety of image file formats.

• One drawback for choosing FOX is the lack of printed documentation. Most of the large chain bookstores (or online booksellers) will have a large selection of reference books for both Tk and GTK+, but you're not going to find any books on FOX programming.

Using the SWin/VRuby Extensions

• SWin and VRuby provide a fast, native solution for developing graphical user interfaces on Windows. If you don't need to run your Ruby application on non-Windows systems, or have some alternative user interface plan for those systems, this may be the right solution for you.

• Documentation is a bit of a problem when you're getting started...