There is only one file type that uses the .UMLCLASS extension:
UML Class Model
Java class description created using the Unified Modeling Language UML; similar to a .UML file, but used specifically for defining Java classes; may include elements, attributes, and operations associated with the class.
UML class diagrams can be created within the Eclipse IDE by selecting, then opening the UML 2.x Diagrams directory and choosing "Class Diagram." While UMLCLASS files store data in an XML format, they can be viewed as a visual diagram within Eclipse.
|Eclipse IDE for Java Developers||Free|
Updated: January 12, 2011