This tiny program tests that OpenGL library is installed and writes on standard output a lot of information about default OpenGL context.
Download glcaps:
Sources of this program are available from this page, in case you're interested.
You can call glcaps with some of the options listed below. Requested OpenGL context will have given capabilities (in case of bit sizes, you provide the minimum requested bit size). If you know OpenGL, then the meaning of these options should be self-explanatory. They are useful to check e.g. is your graphic card able to provide 16-bit stencil buffer.
-s / --stencil-bits STENCIL-BUFFER-BIT-SIZE
-a / --alpha-bits ALPHA-CHANNEL-BIT-SIZE
-d / --depth-bits DEPTH-BUFFER-BIT-SIZE
--accum-red-bits ACCUM-RED
--accum-green-bits ACCUM-GREEN
--accum-blue-bits ACCUM-BLUE
--accum-alpha-bits ACCUM-ALPHA
--accum-bits ACCUM-RED ACCUM-GREEN ACCUM-BLUE ACCUM-ALPHA
--multi-sampling SAMPLES
(1 means "no multisampling")
--single
--double
Also all standard options understood by my OpenGL programs are allowed, see also some notes about command-line options understood by my programs.
Sources of this program are available from this page, in case you're interested.
XWindows users can also use glxinfo program. It's purpose is similar to glcaps (but it's only for GLX, so it's able to write some info like all possible visual configurations).