OpenSG is a scenegraph system for realtime rendering, e.g. for Virtual Reality applications. It is just a library, not a full application.
This documentation contains descriptions of the internal classes and concepts, as well as a tutorial that explains how to use the system.
Swfdec is a decoder/renderer for Macromedia Flash animations. The decoding and
rendering engine is provided in a library that can be used by other
applications
Flirt is an SWF rendering library. Flirt contains a parser for reading SWF
format files, a rasterizer for rendering the vector shaped into bitmaps,
and an actionscript engine
Pango is a library for layout and rendering of text, with an emphasis
on internationalization. Pango can be used anywhere that text layout
is needed however, most of the work on Pango so far has been done using
the GTK+ widget toolkit as a test platform. Pango forms the core of text
and font handling for GTK+-2.x.
