JMatter follows the NakedObjects design pattern, meaning that every domain object should be responsible for its behavior and be behavior complete. But what happens if some requirement can't be tied to a particular domain object? you will require then the well-known service layer, which is exactly what this feature provides. Now you are able to extend your application with "domainless" commands, as shown in the next picture, where the "Say Hi" button is a command exposed by a ServiceObject class (it may have any name you want)
I'm hoping that the UI can be tweaked further into toolbars. Design pattern purists may consider this a step backwards, but actually it is a very useful feature, so useful that the Relevance guys decided to add something similar to Rails (SimpleServices plugin), inspired by Grail's service facilities.
