GL2PS is a C library providing high quality vector output for any
OpenGL application. The main difference between GL2PS and other
similar libraries is the use of sorting algorithms capable of handling
intersecting and stretched polygons, as well as non manifold objects.
GL2PS provides advanced smooth shading and text rendering, culling of
invisible primitives, mixed vector/bitmap output, and much more...

GL2PS can currently create PostScript (PS), Encapsulated PostScript
(EPS) and Portable Document Format (PDF) files, as well as LaTeX files
for the text fragments. Adding new vector output formats should be
relatively easy (and amongst the formats we would be interested in
adding, SVG is first in line). Meanwhile, you can use the excellent
pstoedit program to transform the PostScript files generated by GL2PS
into many other vector formats such as xfig, cgm, wmf, etc.