plotutils
C/C++ library and tools for 2-D raster and vector graphics
.... A Postscript-like API is used both for file export and for graphics animations. A libplot programmer needs to learn only one API: not the details of many graphics file formats.
The package also contains command-line programs for plotting scientific data, such as GNU graph for XY plotting. Many of them use libplot to export graphics. So, they can export graphics in any of libplot's supported formats, such X, png, pnm, gif (bitmap formats), or svg, ps, ai, cgm, fig, pcl, hpgl, regis, tek (vector).