Mathieu Badimon has developed some awesome open source Flash animation classes for creating vector-based 3D-animations. The classes are called “FIVe3D” (Flash Interactive Vector-based 3D) and are written in ActionScript 3 (AS3) — they contain lots of features like Flat Shading, Back Face Culling, Z-sorting, a Bitmap3D class, a Video3D class, a Sprite2D class, Space Drawing functions, Letter Spacing and Text Width. The developer also provides a typography plugin window for Flash that generates a ready AS-file which converts the letters (font) of your choice to shapes in order to transform them in 3D-space.
So FIVe3D is a wonderful 3D-class with lots a nice features. In comparison to the popular Papervision3D-engine it may have some advantages because Papervision3D is bitmap based.