beatassist.eu has released Kuma 508, a free FM synth plug-in for macOS and Windows that features 5 oscillators and a noise generator.
There are 5 FM algorithms and 3 Single Osc modes. Kuma 508 has the possibility to play among 22 extra waveforms per Oscillator. The plugin has 4 filters that can be connected as a modular synth VIA patch cables. There is also a basic but effective Reverb inside Kuma 508.
Kuma 508 is a free product that runs in 64-bit Windows and macOS.
Kuma 508 - Synth Preview: YouTube/-YKcy-LxbnM
Kuma 508 - Presets Preview: YouTube/k_Cu9ENUxC0