Qt OpenGL extension
- OpenGL extension to the Qt GUI software toolkit.
- http://www.trolltech.com/products/qt/indepth/modules

LibSpider
- A library of C++ classes which can be used in making 3D games and applications with OpenGL and GLUT. [Open Source, GPL]
- https://sourceforge.net/projects/libspider/

GtkGLExt
- An OpenGL extension to the GTK GUI library.
- http://www.k-3d.org/gtkglext

libGLobs
- C++ library for RAD (Rapid Application Development) UNIX/Linux OpenGL games and applications.
- http://globs.sourceforge.net

glGUI
- Cross-platform API independent GUI
- http://glgui.sourceforge.net/

GLIntercept
- OpenGL function call interceptor
- http://glintercept.nutty.org/

GLEW
- The OpenGL Extension Wrangler Library is a tool that helps C/C++ developers initialize extensions and write portable applications on Windows, Linux, Darwin, Irix, and Solaris platforms.
- http://glew.sourceforge.net/

GtkGLArea
- An GTK+ GUI library widget for displaying OpenGL renderings.
- http://linux.maruhn.com/sec/gtkglarea.html

GLFW
- Free, open source, portable framework for OpenGL application development
- http://glfw.sourceforge.net/

GLOW
- Cross-platform GUI toolkit for interactive OpenGL programs.
- http://glow.sourceforge.net/

GLE
- Tubing and Extrusion API for drawing tubing, extrusions and sweeps using OpenGL.
- http://linas.org/gle/

GLT
- Portable C++ OpenGL Toolkit including GLUT wrapper and utility classes.
- http://www.nigels.com/glt/

GLE32:
- GLE OpenGL Library for Windows - OpenGL Tubing and Extrusion (GLE) library.
- http://brightideassoftware.com/gle32v2home.asp

UFO
- High level platform-independent GUI for 3D programming with OpenGL.
- http://libufo.sourceforge.net/

GL2PS
- C library for creating high quality vector output (primarily PostScript) from an OpenGL application.
- http://www.geuz.org/gl2ps/

GLTT
- Read and draw TrueType fonts in any OpenGL application.
- http://gltt.sourceforge.net/

Cpw
- Application framework library for OpenGL applications and games.
- http://www.mathies.com/cpw/