SynthMaker, the modular synth design/programming environment that, like SynthEdit, can save its output as a VST effect or instrument plug-in, has recently undergone a fairly major makeover and v0.9.0f has just been released.
Since we last reported any SynthMaker news there has been a lot of development, not least of which is a completely new interface and the ability to add your own graphics to the exported plug-ins.
You can read the recent version history here.