Xen-FMTS 2 is a 4 Operator FM Synthesis VSTi with a
specialized set of features for computer musicians
interested in exploring the vast expressive
possibilities of making music with alternative
intonation systems. It is a freeware 32-bit plugin
instrument for Windows that includes 115 patches, 55
microtunings and 56 partials files.
Effects include Chorus, Lowpass Filter Cascade (Warm
Filter) with 6 dB to 48 dB per-octave filters and
Xen-FMTS 2 is free.