DYI is vector-graphic library that can generate high-quality images and charts, and it is written in Ruby. DYI can generate images in some formats including SVG, PNG and EPS. Outputing a image in SVG, you can use various expressions, for exapmle animation and scripting.

Official web site was renewed. The web site has many demonstrations of DYI. Please come to the website by all means.
http://open-dyi.org/