Weblogic Server 8.1 supports "exploded EAR" deployment
Exploded Archive Directories
An exploded archive directory contains the same files and directories as a jar archive. However, the files and directories reside directly in your file system and are not packaged into a single archive file with the jar utility.
A deployment unit should be deployed as an exploded archive directory, rather than a single archive file, in the following circumstances:
You want to perform partial updates to a deployed application without redeploying the entire application.
You want to use the Administration Console to dynamically edit and persist selected deployment descriptor values for the deployment. (You cannot edit deployment descriptor values in the console for deployments from archive files.) See Dynamically Updating Descriptors for a Deployment Unit for more information.
You are deploying a Web Application that performs direct file system I/O through the application context (for example, a Web Application that tries to dynamically edit or update parts of the Web Application itself). In this case, the modules that perform the I/O operations should have a physical filesystem directory in which to work; you cannot obtain a file when the application is deployed as an archive, as per the specification.
You are deploying a Web Application or Enterprise Application that contains static files that you will periodically update. In this case, it is more convenient to deploy the application as an exploded directory, because you can update and refresh the static files without re-creating the archive.
Does IBM Websphere Application Server 5.1 provide support for exploded EAR deployment?