His thesis on "The structure of composition algebras" was prepared under the advisorship of Prof. Guenter Pilz here at the Johannes Kepler University. It marked the beginning of a successful (and still ongoing!) scientific career in algebra. By now, Dr. Aichinger has published more than 50 articles, mostly in the area of universal algebra. He is also known as an excellent instructor and has been advisor to five Ph.D. students. We are happy to have him at our institute and congratulate him on his achievements during the past 25 years.