EOModelDoc
Overview
EOModelDoc is a command line tool to generate HTML documentation of a set of EOModels. It is a replacement for EOReporter (which will not work on Leopard and newer releases of OS X). EOModelDoc was funded by the Apple iTunes Store and released to the community.
On the WOLips side, from version 3.3.x, Entity Modeler has a Documentation tab on all of the elements of a model that lets you record HTML documentation for your model, entities, attributes, etc. There is even an HTML preview. You can then run eomodeldoc to produce documentation much like javadoc for your model.
Future Plans
From Mike Schrag: There's not a nice build process for this one either, yet, because it includes all of the eclipse dependencies in the single jar. Eventually I'll make this nicer and include it actually inside of Eclipse. There are also modifications to the ERNeutralLook coming soon that will display popup help for you models based on the model documentation.