Kabeja is a Java library for parsing CAD data (i.e. Autodesk's DXF format) and converting to SVG (dxf2svg). You can use Kabeja from the command line or embed it into your application. It includes a plain DXF2SVGViewer and integration into the Cocoon XML Web development framework and the Inkscape SVG editor.
Apache XML Graphics Commons is a library that consists of several reusable components used by Apache Batik and Apache FOP. Many of these components can easily be used separately outside the domains of SVG and XSL-FO. You will find components such as a PDF library, an RTF library, Graphics2D implementations that let you generate PDF and PostScript files, and much more.