Tethys 1 is a free VST/standalone synthesizer.
 

Based on the architecture of the PAiA Proteus 1 (and in no way meant to sound like one.

I just really liked the simplicity of the design and the funky stepping program manger, unfortunately that drove hosts crazy so had to be left out.

Combo Model V is a freeware virtual combo organ, modelled after a well-known combo organ from the 1960s.

Combo Model V features