umlc contains two parts
1. UltraViolet
UltraViolet is based on the great Violet UML editor(http://horstmann.com/violet/).
UltraViolet is a UML class diagram editor and code generator. It currently integrates with JMatter (http://jmatter.org) to provide a easy way to create an application without any coding.

2. UML compiler
It also has been retrofitted to support a simple UML class diagram text language, that with the built in umlc compiler, will genetated UML and run the code generator.