The Tiberium system is an open platform for the deployment of applications in a PaaS philosophy structure. The final project should be as most compatible as possible with the current Heroku philosophy and one should be able to deploy their apps to both systems.
The file contains structures for the creation of the sun files required for deployment in the various tiberium nodes.
A sun file is a plain tar file contain a specific structure of directories that is meant to be a portable format for distribution of an application across multiple nodes.