High Quality Content by WIKIPEDIA articles! Produced by the Environmental Systems Research Institute (Esri, formerly ESRI), the Esri International User Conference (Esri UC) is the world`s largest event dedicated to geographic information system (GIS) technology. It is held annually in the United States, usually for one week in July at the San Diego Convention Center in San Diego, California. The Esri UC dates back to 1981. In 2008, conference attendance grew to more than 14,000 attendees.