OpenGL User Interface Library (GLUI) is a C++ user interface library based on the OpenGL Utility Toolkit (GLUT) which provides controls such as buttons, checkboxes, radio buttons, and spinners to OpenGL applications. It is window- and operating system independent, relying on GLUT to handle all system-dependent issues, such as window and mouse management.
It lacks the features of a more full-fledged GUI toolkit such as Qt, wxWidgets, or FLTK, but it has a very small footprint and is extremely easy to use. A research or demonstration program that originally only uses GLUT can be given a useful control panel using GLUI in a short time, even by someone new to the toolkit.
It was first written by Paul Rademacher to help him with his academic work. It is now maintained by Nigel Stewart.
Weaknesses include the lack of a properly functioning file chooser (perhaps the most frustrating omission) and mediocre responsiveness.