Here is a link to some sample OpenGL code to demonstrate how to render correctly for the Showcase Dome in ITS Manning.  Four 1400×1050 views of the scene (laid out in a 2×2 grid in a borderless window) must be rendered with specific fields of view and view directions.  This code should be relatively straightforward, and explain the basics of what it would take to add dome-rendering to your own code.

A teapot rendered for the dome.