The Java programming language used to be called Oak. The person who made Java is James Gosling. He worked at Sun Microsystems. He named it Oak because there was a tree with that name outside his office.. Then they had to change the name to Java. This happened in 1995. The reason for the change was that there was another company called Oak Technologies and they did not want to have the name as that company. So they changed the name of the Java programming language from Oak, to Java.