gltools has been designed with the needs of numerical analysts in mind. Thus, unless many other packages available, it can be used to enhance existing codes with interactive or non-interactive graphical output.

It enhances the OpenGL API with the following additional functionality:
* Multiple independent windows.
* Basic interactive handling through mouse and keyboard.
* Interactive three-dimensional rendering volume.
* Character output.
* High quality frame dump in encapsulated postscript format.
* MPEG video recording of window contents.
* Piecewise linear function rendering on two- and three-dimensional
simplex meshes (landscape view of plane sections, isolevel surfaces, isolines)
with an universal, callback based mesh interface