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.
Jim (Java Image Manager) is a program for managing your personal images (photos, etc.). While Jim is really easy to use, its tagging technology is quite powerful. A plugin system makes it easy extensible with new technologies. It runs on several operating systems (including Windows, Linux and many more); all you need is a Java Runtime Environment.