A Zope update from version 2.8.0 to version 2.8.8 was made on our Linux servers. This enabled the Plone CMS to be updated to version 2.5. All existing Plone instances were migrated.
This provides an improved performance as well as the latest security patches. Editors profit in addition from an improved set of functions.
Apart from a series of many tests, all sites were subjected to a visual check while the design of the sites remained unchanged.
All sites remained in operation during this entire time since the updates and the migration were carried out on a redundant second system.
Nevertheless, if you should detect unwanted changes to your home page contact us at: email@example.com.
Plone 2.5 :: http://plone.org/products/plone/releases/2.5