Ehcache 1.5.0 is a major new release.
New Features

    * Added JGroups Implementation. Thanks to Pierre Monestie for the patch(es) for this. Though new to the core distribution JGroups replication has been in production use in a large cluster for the last year. JGroups has a "provided" scope. So, anyone wishing to use this form of replication will need to add it to their dependencies.
    * CachingFilter performance improvements
    * Constructs performance improvements
    * added loadAll() to the loader implementation to enable preload without specifying keys.
    * diskPersistent now can be used with caches that use only MemoryStore in normal use but want to persist to disk
    * DiskStores are now optional. The element is now non-mandatory. This will simplify configurations particularly where multiple CacheManagers are being used. If one or more caches requires a DiskStore, and none is configured, java.io.tmpdir will be used and a warning message will be logged to encourage explicity configuration of the diskStore path.
    * The default RMI based cache replication can now configure a RemoteObject port so that it can be easily configured to work through firewalls. This is done by adding a new property remoteListenerPort to RMICacheManagerPeerListenerFactory to enable it to be specified.
    * Added a new system property expansion token "ehcache.disk.store.dir" to DiskStore configuration which can be used to specify the DiskStore directory on the command line or in an environment variable.

          e.g. java -Dehcache.disk.store.dir=/u01/myapp/diskdir ...

    * Added the ability to specify system property tokens using $tokenname in ehcache.xml which are then replaced when the configuration is loaded.
    * Updated the remote debugger with enhanced reporting and better documentation (See Logging page in the documentation).

      The new version prints a list of caches with replication configured, prints notifications as they happen, and periodically prints the cache name, size and total events received.

      Note that the debugger is gaining more attention and is now distributed in its own tar ball. It has also moved to its own pure maven build and has additional testing.

Summary of Bug Fixes

    * CachingFilter bug fixes for various rare edge conditions
    * Major speed up to shutdown process when diskPersistent is not being used
    * Fixed various shutdown exception when both Hibernate and Spring both try to destroy caches

http://ehcache.sourceforge.net/changes-report.html#1.5.0