Nabla by Full Bucket Music
KORG DL-50 (Korg Delta) freeware simulation, develope by Full Bucket Music. Great retro synth strings and fat bass synth tones. In addendum to the original machine, Nabla features a phaser, a delay and true polyphony.
Best Free 64 bit VST/AU Strings and String Machines
Sonatina Viola by bigcat Instruments
VST Viola based on samples, with sustain, staccato and pizzicato variations.
The deputy Mark II by Full Bucket Music
A high quality classic string machine developed by Full Bucket Music, with ensemble and phaser FXs, up to 61 voices polyphony, filter and LFO.