Justin Robert’s Mothman 1000 is a free 2 oscillator software synth VSTi plugin for Windows that features a subtractive analog oscillator and a phase distortion oscillator.
Both oscillators feature modulating LFO / HFOs (low and high frequency) as well as VCFs for each oscillator, VCF 1 includes an ADSR input section. The high frequency modulation creates FM synthesis type sounds. Mixing this with the phase distortion and subtractive sounds makes for a lot of possibilities. You can also use the L(H)FOs for standard LFO fx. The L(H)FO on OSC 1 is routed to the amp section of OSC 1 and the L(H)FO of OSC 2 is routed to the modulation depth of OSC 2, playing with this can create very interesting ring modulation and FM type sounds.
There are 32 built in presets that range from warm pads, Casio emulation, metallic craziness, warm analog basses and drums. It also features an oscilloscope just for fun.
To install the VST just extract it to your VST folder and restart your DAW.