I would suggest cairo, Cairo is a 2D graphics library with support for SVG file output.
The cairo API provides operations similar to the drawing operators of
PostScript and PDF. Operations in cairo including stroking and filling
cubic Bézier splines, transforming and compositing translucent images,
and antialiased text rendering. All drawing operations can be
transformed by any affine transformation (scale, rotation, shear,
etc.)
Cairo is implemented as a library written in the C programming language, but bindings are available for several different programming languages. Which include Perl, Python, Ruby and so much more.
It also has several Toolkit Bindings. GTK+ 2.8+ has full support for cairo for example.
Also has and experimental backends with OpenGL. Which benefits include Easily integrate features like PS-, PDF-, SVG-support to your OpenGL-application (may need additional libraries).
Cairo is free software and is available to be redistributed and/or
modified under the terms of either the GNU Lesser General Public
License (LGPL) version 2.1 or the Mozilla Public License (MPL) version
1.1 at your option.