eZ Publish Platform (5.4.x) was a transitional version of the eZ CMS, bridging the gap between the earlier generation called eZ Publish (sometimes referred to as legacy), and the current eZ Platform.
eZ Publish Platform introduced a new Symfony-based technology stack that could be run along the old (legacy) one. This fluid change allows eZ Publish users to migrate to eZ Platform in two steps, using the 5.4.x version as an intermediary stepping stone.
