FTGL 2.4.0
FTGL User Guide

Introduction

OpenGL doesn't provide direct font support, so the application must use any of OpenGL's other features for font rendering, such as drawing bitmaps or pixmaps, creating texture maps containing an entire character set, drawing character outlines, or creating a 3D geometry for each character.

More information can be found on the OpenGL website:

Most of these systems require a pre-processing stage to take the native fonts and convert them into a proprietary format.

FTGL was born out of the need to treat fonts in OpenGL applications just like any other application. For example when using Adobe Photoshop or Microsoft Word you don't need an intermediate pre-processing step to use high quality scalable fonts.

Documentation

Additional information