Over the course of more than thirty years, John Quijada has used his training in linguistics to develop the constructed language Ithkuil. His work is well-known among the niche group of hobbyists known as "conlangers" (inventors of constructed languages). Various academics in Russia and Ukraine have also shown great interest in the language, resulting in Quijada traveling to both countries in 2010 and 2011 for speaking engagements. John is also interested in quantum physics and the quantum interpretation problem. He and his twin brother, Paul, a professional artist, have co-written a novel, Beyond Antimony, which explores the philosophical implications of quantum physics in the context of a political thriller/science fiction story. John's other interests/hobbies include travel, eclectic literature, philosophy, history, art, music, cosmology and astronomy, protozoology, cinema, camping, hiking, and cooking. He lives in Northern California with his wife and two cats.