Foo YC-20 is free software emulation of the YC-20 divide-down combo organ from the 60's. The plugin is available for Linux, Windows and Mac.
Note: YC-20 takes quite a bit of CPU power, it does not have touch vibrato.
YC-20 is available now as a free download for Linux, Windows and Mac.
Eurorack module puts General MIDI sound set under creative CV control