Just spotted this posted at Beyond3d by Dave Baumann.
Delphi3D has posted and OpenGL Cel Shading (or 'Toon Rendering') demo using GL_ARB_vertex_program and GL_ARB_fragment_program. Dephi says that "The demo renders object outlines by performing an edge detection filter in image space. The "cel shading" look is achieved with simple vertex lighting combined with a dependent texture read. The demo also uses a shadow map for shadowing. A GeForce FX or Radeon 9500 or better is required to run the demo.
Download OpenGL Cel Shading Demo
Delphi3D has posted and OpenGL Cel Shading (or 'Toon Rendering') demo using GL_ARB_vertex_program and GL_ARB_fragment_program. Dephi says that "The demo renders object outlines by performing an edge detection filter in image space. The "cel shading" look is achieved with simple vertex lighting combined with a dependent texture read. The demo also uses a shadow map for shadowing. A GeForce FX or Radeon 9500 or better is required to run the demo.
Download OpenGL Cel Shading Demo