Prysm Audio has released Monosc, a freeware single oscillator unison synthesizer in VSTi plugin format for Windows. Monosc is a single-oscillator unison synth, perfect for electronic basslines, leads & plucked sounds. Monosc is available for free download via Prysm Audio (2.6 MB download size, 32-bit VSTi plugin format for Windows). This is a simple virtual analogue synthesizer, designed for easy creation of basses and lead sounds. It features a single oscillator with 4 waveforms, a filter with 4 filter types, and 16-voice unison.
Prysm Audio has recently released another interesting freebie which can be found on the Products page on their website. It’s a freeware SFZ player with simple controls and a built-in reverb.