make the engine Microsoft centric. You should target OpenGL 2/3 ES / WebGL. That is the common denominator.
Actually, you should use a DX compatible subset of OpenGL ES 3/WebGL 2, it is supposed to be fully compatible with OpenGL 4.3.
Though, if you only want vectorgraphics then the sane thing to do would be to rip out the SVG engine in Chrome or FF and create a full SVG DOM in D.
