Virtual Organs use Personal Computers and software for tone generation, rather than dedicated hardware tone generators. Their suppliers are very small companies or hobbyists who purchase consoles from one source, keyboards, amplifiers, power supplies, etc. from others, and PCs and software from still others.
Virtual Organ suppliers have included, Martin, VPO, Phoenix Organs, Noorlander, among others, some of which are no longer in business. The photographs below were taken of various virtual organs.