The Knowledge Base Versions Tool Window shows a tree representation of an application's life. The order of the tree is chronological, with the most recent nodes appearing closer to the top. The root node, known as the main Development Version, represents the application's major evolution path. Other nodes may be either a Frozen Version, representing special milestones in the application's life, or a Development Version, representing other evolution paths.
The following picture shows a sample tree with some GeneXus milestones and evolution paths.

The Knowledge Base Tool Window is used to view and manage the application's Frozen and Development Versions, and to make a version active (or current), so it can be analyzed or changed. Context menu options available for each node type are described in Frozen Versions and Development Versions respectively.
At the begining, we start with only one node, which has the same name as the Knowledge Base. We don't have to do anything to get this node, as it is created when we create the KB.
This node is the root node of the trunk:
Fig2.- First node of the version tree
As we start working in our application, we will need to add milestones (frozen versions). This is done by right-clicking on the root's trunk node, and selecting "Freeze" from the pop-up window.
So we have the frozen version labels:

Fig3.- Adding a frozen version lo label the KB variations in the version tree
To add a new development version we need to right-click on a Frozen Version and select "New Version" from the pop-up window. In the images below we can see a diagram structure of the development cycle in a particular application, and how the Knowledge Base Tool Window should look in order to store it.

