Visit http://screenlets.org to get the Latest file and download it , installing is not that easy as there is no BINARY installer yet (like rpm or .deb) and Still have difficulty to get manager running. still the individual screenlets (like clock,calender,notes) are easily runnable. Still in development, the author has done incredible job for creating small foot print and good on resource usage (less cpu/ram) application . core language I found used is "Python" plus its Opensource
Following is screenshot of all widgets running (~800kb):-
Video of how I fireup the screenlets (~ 1.3mb) :-
