I'd say there should be two different pages: one for end-users, and one for developers. In his defense I'd argue the users of Java are developers, in which case they need to know specifically what it is. For end users who need it installed on their machines, the description should be "Java is a necessary plugin to make many of your favorite applications work correctly."

In the case of other tools, a lot of companies focus on useless buzzwords like "it's a cloud-enabled multi-tier architecture et cetera" instead of focusing on what the person using it cares about: "it's a content management system for blogs." OK, got it.