MadButterfly ( http://www.assembla.com/spaces/MadButterfly) is a toolkit for GUI environment. It is designed for embedded system. It make GUI designers and programmers work seperately. Designer export their artifacts to files with SVG format. MadButterfly provides a tool to translate graphics in SVG into C code and a framework that programmer can manipulate graphics. It works like a Javascript programmer to manipulate DOM object. Programmers using MadButterfly manipulate objects corresponding to SVG tags to interact with users of application.
Inkscape is an open source project to provide a vector graphics editor. Inkscape saves graphics in SVG format. You can use it to design your graphics that can be used with MadBufferfly.