KV331 Audio and Beat Magazine have released the free (with magazine) SynthMasterBE software synthesizer plug-in. It's available with Beat Magazine issue 86 (02/13) in VST and AU formats on Windows and Mac OS X.
SynthMasterBE is a cut-down version of SynthMaster with the following feature set:
Single layer synth with:
-2 'basic' oscillators.
-2 modulators (sub-oscillators) that can modulate phase/frequency/amplitude of oscillators at audio rate.
-1 digital filter with LP/HP/BP/BS modes, before/after filter distortion curve.
-1 arpeggiator with up to 8 steps.
-4 ADSR envelopes (2 are pre-patched as amplitude and filter envelopes).
-1 Step/Glide LFO and 1 Triangle/Square LFO.
-Polyphony: up to 12 voices.
-Unison: up to 2 voices.
-Osc Voice Stacking: up to 4 voices.
-Modulation Matrix: 10 slots available.
Oversampling: 2x (at Good Quality).
Delay, Chorus and Reverb effects.
70 Factory presets by Michael Kastrup, Rob Lee and Aiyn Zahev.