The FOX toolkit is an open-source, cross-platform widget toolkit, i.e. a library of basic elements for building a graphical user interface (GUI). FOX stands for Free Objects for X. It features a hard-wired Windows 95-style theme available for both Microsoft Windows itself as well as the X Window System (which is used on many UNIX and UNIX-like operating systems). The FOX toolkit has been released under the GNU Lesser General Public Licence. Development began 1997 by Jeroen van der Zijp while he was affiliated at CFDRC. Since then, Jeroen van der Zijp maintains the core library and test applications, with the help of user community. The FOX toolkit is written in C++, with language bindings available for Python, Ruby and Eiffel. The FOX source code distribution supports building with many different (commercial and free) C++ compilers. Cross-platform compatibility FOX differentiates itself in the following way from other cross-platform toolkits: Tk is a cross-platform toolkit but does not have all of the widgets that FOX considers desirable. Qt up to version 4.5 used to have a licensing model that required a commercial license in some cases where FOX would not. wxWidgets promotes the use of native widgets on each supported platform. FLTK is a fast, low-footprint library that supports rapid application development, and requires less code to use, but lacks advanced widgets. All of these toolkits have some support for programming natively on the classic Mac OS and/or macOS platforms, which FOX currently does not support. FOX uses a technique similar to the Java Swing-style approach to display a graphical user interface to the screen, using only graphical primitives available on that platform, as opposed to the original Java AWT-style approach which used native widgets. This means that applications will have a similar look and feel across platforms. In theory, porting FOX to a new platform should also be easier than implementing support for native widgets. On the downside, it usually means that FOX applications will look and feel different from native applications for those platforms, which some users may find confusing. Also, certain native platform features may not be available immediately, such as comprehensive printing support or internationalized input handling, because they will need to be re-implemented in a cross-platform way before they can be used in FOX. Some applications, like Xfe File Manager, allow changing the color scheme to better integrate with the system's theme colors. On Arch Linux,