Now that the 8.5 Designer client is Eclipse based, there is a new UI. The default perspective in 8.5 is the Domino Designer perspective. There are other perspectives available in Domino Designer 8.5, each suited to a particular task. You can select a different perspective from the menu, select Window | Open Perspective | Other, as seen in the following screenshot:

Perspectives can be customized to suit individual preferences. One way is by resizing the views and editors.

You can resize views and editors in one of two ways. Click the Maximize/Restore button located in the title bar of the view or editor. Or, click and drag the border of a view or editor.

Views and editors can also be hidden by clicking the view Close button.

Use the menu pick Window | Show Eclipse Views to reopen closed views. You can use this menu pick to open any Eclipse view, including those from other perspectives.

To return to the current perspective's default layout use the menu pick Window | Reset Perspective....