Image-Line Sytrus v2.6.12
Sytrus is a powerful and versatile synthesizer featuring six customizable operators for FM (Frequency Modulation) and RM (Ring Modulation) synthesis, plucked string synthesis, 3 filter modules, an effects module with chorus, three delay lines and unique programmable unison mode.
The rich implementation characteristics of Sytrus allow for an extremely wide range of sounds, including bass lines, bells, pads, drums, pianos, strings, organs and even entire drum and synth loops (in a single patch/note), made possible by the completely customizable envelopes supported by each module.
Along with this flexibility comes complexity. However, if you stick with Sytrus and study this help file (there's a easy step-by-step tutorial here), we are sure you will find Sytrus to be one of the most rewarding plugins in the Image-Line library.