Quandrant is the Microsoft Oslo’s Visual DSL editor.
Still in alpha stage, was only disclosed to the PDC’08 attendees in October.
Thanks to Stwphen W. Thomas we can take a look on it (Flash video).
Quadrant provides a generic visual editor for creating and exploring Oslo models. The models are stored in a MS SQL 2008 Database. The samples shown in the video ilustrates selecting & manipulation objects and a workflow (a la BPMN) notation.