Polymeria UML is a set of Polymer Web components rendering an Eclipse UML2 model file. Because of custom elements compatibility constraints (dash needed), the model file cannot be rendered without a transformation of UML element names. The project started following my discovery of the Polymer project. A post on my blog details my early problems.
An early sample is available and shows the modifications between the initial UML2 model and the web components. If you want to play with the components, the installation with Bower is documented in the GitHub pages.