In my lab "knowledge map" is one of the internal trendy buzzword, we use it to model course content and concepts to be acquired by students. I personally use a

In my lab "knowledge map" is one of the internal trendy buzzword, we use it to model course content and concepts to be acquired by students. I personally use a graph-based lexical system which allows me to create dictionary apps super quickly (basically by just transforming the initial resource, sometime by creating additional UI components). In industry Google use it (they coined the term), otherwise I don't know. In the open data world DBpedia is the reference and is the target of a lot of inbound links.