EtoileUI is a high-level OOUI toolkit that provides a uniform tree
representation for graphical objects on top of the AppKit. All User Interface
concerns such as layouts, event handlers, styles, model objects etc. intends
to be implemented as pluggable aspects. It also shares the same interfaces as
other CoreObject systems. The combination of these three key features makes
possible to inspect and reshape both User Interface and model objects at
runtime through direct manipulation. It comes with a library of layouts
where each one encapsulate a custom and pluggable UI presentation.

LICENSE: BSD

WWW: http://www.etoile-project.org/