Good architecture contains patterns. But which pattern does a given class follow? The task of xMolecules is to express this explicitly. (see www.xmolecules.org) For different programming languages (Java, .net, and PHP) the possibility of annotating code accordingly is given. It becomes easier for the human reader to understand which pattern a piece of code follows. It also makes it possible for architecture rule checkers like JQAssistant, ArchUnit, etc. to check the rules. Finally, code generators can use the info to reduce boilerplate code. In this talk, this brand new library will be presented by one of its creators.