Free graphical libraries/GUI

• f90gl: "f90gl is a public domain implementation of the official Fortran 90 bindings for OpenGL." For Linux, Mac OS X, Solaris, UNIX, Windows. Public domain.
• ftcl: Combining Fortran and Tcl in one program — A Fortran–Tcl/TK interface. Open-source.
• g2 graphical library: "g2 is an easy to use, portable and powerful 2D graphics library." For Linux, Mac OS X, OpenVMS, Solaris, UNIX, Windows. GNU LGPL.
• GrWin Graphics Library: "GrWin Graphics Library is a free graphics routine library for Fortran and C/C++." For Windows. Open-source.
• japi (Java Application Programming Interface): "An open source free software GUI toolkit." For Linux, Mac OS X, Solaris, UNIX, Windows. GNU LGPL.
• Platform Independent Library for Fortran 90/95: "The portable way [for] creating GUIs, doing file IO etc. This library is an attempt to build a platform and compiler independent library for Fortran 9x." For Linux, Mac OS X, UNIX, Windows. GNU LGPL.
• PLplot – a Scientific Plotting Library: "PLplot is a library of functions that are useful for making scientific plots." For Linux, Mac OS X, MS-DOS, Unix, Windows. GNU LGPL.
• Xeffort: "Xeffort is a free, open-source library for building GUI applications in all flavors of Visual Fortran." For Windows. Open-source.

Proprietary/non-free graphical libraries/GUI

• DISLIN: "DISLIN is a high-level plotting library for displaying data as curves, polar plots, bar graphs, pie charts, 3D-color plots, surfaces, contours and maps." For DOS, Linux, Mac OS X, OpenVMS, UNIX, Windows. "Free for non-commercial use" (but not free).
• SansGUI: Requires Microsoft Visual C/C++ 6.0+ or Compaq Visual Fortran 6.1+. For Windows.
• Winteracter: "The Fortran 9x GUI Toolset." For Linux, Mac OS X, Windows.