In Enterprise Server, domain.xml is the main server configuration file. In Application Server 7, the main server configuration file was server.xml. The DTD file of domain.xml is found in lib/dtds/sun-domain_1_1.dtd. The upgrade tool included in Enterprise Server can be used to move from server.xml in Application Server 8 to domain.xml in Enterprise Server.
The DTD file for Enterprise Server is fully backward compatible with the corresponding file for DTD file for older versions of Application Server.
In general, the configuration file formats are not backward compatible. The following configuration files are not supported:
server.xml (replaced by domain.xml)