B8 Organ is an virtual organ instrument for Windows.
It's not a B3, not even a B4…in fact it's a B8! It's basically a reproduction of the old organs of the 60's-70's.
It has 9 oscillators, switchable between sine and saw wave, with drawbars, vibrato, chorus and reverb. Sine waves results in tones typical of a church organ, or hammond-type sounds. Saw waves sound more like old combo organs, like Farfisas, Davoli, Crumar, for example.
B8 Organ is available as a freeware VST instrument plug-in for Windows PC.