This is a 5-voice polyphonic FM synth built with Max. The Multiball object lets you control 5 carrier frequencies and harmonicity ratios at the same time. Additional graphical controls let you tweak further the synthesis parameters, note durations and ADSR envelopes.
Just open the jzml project in the JazzEditor and set the target 0 port to 8000. You can launch the standalone application for your OS or use the max patch file if Max is installed on your machine.
With a very straight-forward interface, you can achieve pretty cool sounds with great control on the tone. Have fun !