These applications provide the tools needed to program the synth which were missing when it was in production by Yamaha. The synth was discontinued after two years, probably in part due to its complexity (particularly the formant sequencing), poor front-panel controls, brief manual and limited polyphony.
The Yamaha FS1R is a sound synthesizer module, manufactured by the Yamaha Corporation from 1998 to 2000. Based on Formant synthesis, it also has FM synthesis capabilities similar to the DX range.