Many different UI components in NetBeans are actually Explorer views of nodes.
The exact properties of a node may be displayed and edited with the Property Sheet.
The Explorer is really an abstraction that needs a view to actually display the nodes.
Provides Swing UI components that render provided node hierarchy in different ways (as a tree, list, icons, set of properties and many other).
It is possible not to show icons in OutlineView and in TreeView and it's descendants. Methods OutlineView.setShowNodeIcons(boolean)/isShowNodeIcons() and NodeRenderer.setShowIcons(boolean)/isShowIcons() are added for this purpose.
Now it's possible to turn off the default autocomplete for in-line combo box editors by using "canAutoComplete" attribute to Boolean.FALSE on appropriate FeatureDescriptor.
PropertySheet class has new methods which allow subclasses to provide custom popup menu, check expansion state, expand/collapse property categories, retrieve the selected property.
In order to conveniently set attributes to column properties, setPropertyColumnAttribute() method is added to OutlineView. After OutlineView.setProperties() method was deprecated, the preferred way how to add columns is via addPropertyColumn()/setPropertyColumns(). But then there's no Node.Property to set additional attributes on. This is why setPropertyColumnAttribute() method is introduced.
Added OutlineView.isQuickSearchAllowed(), OutlineView.setQuickSearchAllowed() and OutlineView.setQuickSearchTableFilter() methods to control quick search functionality on OutlineView. Interface QuickSearchTableFilter introduced to provide custom table cell data for quick search.
For general overview of the concepts related to nodes and explorers, together with code samples, see chapter 7, of NetBeans Platform for Beginners by Jason Wexbridge and Walter Nyland.
The sources for the module are in the Apache Git repositories or in the GitHub repositories.
XXX no answer for deploy-dependencies
Read more about the implementation in the answers to architecture questions.