This section defines the versioning terms that are important to understand.


A resource under the control of the version management system used by ATG Content Administration—for example, foo.html. An asset maintains a list of its own asset versions.

Asset Version

A specific version of an asset—for example, version 2 of foo.html. Each asset version has a unique version number. The initial version of an asset is always version 1. When a new asset version is created, it is immediately assigned the next available version number.

Head Version

The most recent version of an asset for a particular branch.

Development Line

In other version management systems, a set of assets is often called a line of development or code line. In ATG Content Administration, a development line is one of the following:


The VersionManager service manages all development lines that are created and used in the content development environment. It is the central factory for creating, storing, and querying all versioning objects: development lines, assets, and asset versions. ATG Content Administration provides a default VersionManager, which is located in Nucleus at /atg/epub/version/VersionManagerService.

The development lines managed by the VersionManagerService are stored in the /atg/epub/version/VersionManagerRepository, which is also provided with ATG Content Administration.