QuesoGLC is a free implementation of the OpenGL Character Renderer. The OpenGL Character Renderer (GLC) is a state machine that provides OpenGL programs with character rendering services including scale and rotate text and draw text using lines, filled triangles, or bitmaps. 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.
libtholoura is a text-image distortion library, which is useful for sites that want to ensure that a human (and not a bot) is viewing pages. It is optimized to produce images of strings distorted in a way that makes it impossible for an OCR to read, but humans can. The library takes a string (preferably ASCII) string and is able to dynamically produce PNG indexed images. The distortion filters are external plugins.
SILGraphite (formerly OpenGraphite) is a project within SIL's Non-Roman Script Initiative and Language Software Development groups to provide extensible cross-platform rendering capabilities for complex non-Roman writing systems. It consists of a rule-based programming language, Graphite Description Language (GDL), that can be used to describe the behavior of a writing system, a compiler for that language, and a rendering engine that can serve as the backend of a text processing application. SILGraphite renders TrueType fonts that have been extended by means of compiling a GDL program. It is currently being integrated into Gecko/Mozilla through the SILA project, a GNU/Linux port is also underway, and there are plans for OpenOffice.org and Abiword integration.