Most portlets written for WebSphere® Portal 5.0 will run unchanged in WebSphere Portal 5.1. Some of the Portlet 5.0 APIs are now marked as deprecated, but are still available on WebSphere Portal 5.1. However, some portlets will have to be migrated as described in this topic. It is recommended that you migrate portlet projects to the version of WebSphere Portal that your portlets will be installed on.
To migrate portlet applications for WebSphere Portal 5.0 to 5.1, do the following: