http://www.microsoft-watch.com/article2/0,1995,1489438,00.asp
Xen, a new programming language coming out of Microsoft Research and developed in conjunction with the University of Cambridge, promises to bring together three disparate but integral components of programming, wrapping them together in .Net. Xen's creators use a geometric metaphor to illustrate this conjoining, calling the language a means to program with "circles, triangles, and rectangles."
Source: http://dotnetjunkies.com/WebLog/slog/archive/2004/01/21/5866.aspx