A modular synthesizer manufacturer based in Glendale California, and named after its owner, Cynthia Webster. (The company is actually named Cyndustries, but Cynthia is the brand name that appears on the products.) Cynthia got its start designing specialized modules that filled in gaps in the Modcan-A module lineup, many of them based on circuit boards from Catgirl Synth. Over the past few years, as Modcan has expanded its model line, Cynthia has turned to offering a smaller lineup of specialized modules which are available in all five of the most popular formats -- Dotcom, Eurorack, Frac, Modcan-A, and MOTM. One notable and popular product is the Zeroscillator, a VCO with through-zero modulation capability.
As of May 2017, it appears that the company is no longer doing business.