Microwindows for Personal Basis Profile - Hosts the modified Microwindows source, with some changes were necessary for compatibility with Personal Basis Profile. - http://www.experimentalstuff.com/Technologies/mwpbp/
PicoGUI - A client/server GUI architecture designed mainly for embedded systems, with emphasis on scalability and separation of content and presentation. - http://picogui.org
MicroWindows - An Open Source project aimed at bringing the features of modern graphical windowing environments to smaller services. - http://www.microwindows.org/
Fresco - A windowing system derived from a powerful structured graphics toolkit originally based on InterViews. Source code, documentation, and screenshots. - http://www.fresco.org/
Yahoo Groups: giotto-gui - Mail list and group for Giotto embedded portable GUI, light clone of MicroWindows. - http://groups.yahoo.com/group/giotto-gui/
GGI Project Homepage - This aims to create a portable graphics interface - http://www.ggi-project.org/