You can download binaries, look at online documentation, etc, at the OpenScenGraph web site

On an SCF Linux machine ...

To make the examples

% cd src
% make all

To run osganimate

% run_osg osganimate

To run simple_viewer

% run_osg simple_viewer sph.obj

To run the supplied osgviewer

% run_osg osgviewer sph.obj