If you want to run the Behaviour Composer on your own server the easiest solution is to install Google GWT and Google App Engine for Java and the Google plugin for Eclipse.
The source code can be obtained from https://code.google.com/p/modelling4all/source/checkout.
Deploying to the Google App Engine is a single click using the Google plugin for Eclipse.
The Google App Engine has generous free quotas and reasonable prices. There is an open source project that supports the Google App Engine API that one can run on any server. It has not been tested to see if it really can run the Behaviour Composer.