I think the keyword is "text-heavy". Rendering 256 characters into a texture to use with WebGL is one thing, but what about unicode, or readability at small sizes? I'm honestly asking, I'd love to hear about ideas or libraries etc.
In OpenGL you can use CoreGraphics to render into a context and convert that data to a texture. This could be done for each string, but doing so you loose the power of the underlying implementation. If there are libraries that make this easier I am yet to come across them.
