Open GL has no built-in capability for drawing text. Open GL provides lower level primitives like lines and curves and meshes. Open GL also provides texture compositing.
There are some free and some open text drawing/font solutions for Open GL. You can use the GLUT library up to a point.
On Mac OS X, the traditional way to mix Open GL and Cocoa text is by rentering the text into a texture and then using Open GL to composite the texture.
The sample I think you want is
http://developer.apple.com/samplecode/CocoaGL/index.html
See other samples at
http://developer.apple.com/samplecode/GraphicsImaging/idxOpenGL-date.html
For modern Mac OS X, you might do what you want with "layer backed views" to use a Cocoa text view as an Open GL texture. See also CATextLayer
http://developer.apple.com/samplecode/CALayerEssentials/index.html
