David A. Smith Andreas Raab David P. Reed Alan C. Kay Croquet: A Menagerie of New User Interfaces. 4-11 2004 conf/c5/2004 C5 http://csdl.computer.org/comp/proceedings/c5/2004/2166/00/21660004abs.htm db/conf/c5/c5-2004.html#SmithRRK04