The OpenGL Character Renderer (GLC) is a state machine that provides
OpenGL programs with character rendering services via an application
programming interface (API).

The character rendering services provided by GLC has some significant
advantages over platform specific interface such as GLX or WGL:

1. The GLC API is platform independent. Since most nontrivial GL
   applications render characters, GLC is an important step toward the
   goal of truly portable GL applications.
2. The GLC is simpler to use. Only two lines of GLC commands are
   required to prepare for rendering characters.
3. GLC provides more ways to exploit the rendering power of OpenGL.
   For example, a glyph can be drawn as a bitmap, a set of lines, a
   set of triangles, or a textured rectangle.
4. GLC provides better support for glyph transformations. For
   example, GLC supports rotated text, which is unavailable in GLX.
5. GLC provides better support for the large coded character set
   defined by the standards ISO/IEC 10646:2003 and Unicode 4.0.1

QuesoGLC is a free (as in free speech) implementation of the GLC.
QuesoGLC is based on the FreeType library, provides Unicode support
and is designed to be easily ported to any platform that supports
both FreeType and the OpenGL API.

WWW: http://quesoglc.sourceforge.net/