It is possible. The following code will show the ribbon and add a tab with a group to it. Then it will add a button tool to the group.
manager.Ribbon.Visible = true;RibbonTab tab = manager.Ribbon.Tabs.Add( "tab" );RibbonGroup group = tab.Groups.Add( "group" );
ButtonTool rootTool = new ButtonTool( "button" );manager.Tools.Add( rootTool );
ButtonTool instanceTool = (ButtonTool)group.Tools.AddTool("button");