Friends, The Worldwide LC Simulation Working Group is preparing a document that lists the requirements for a common detector simulation program. See message posted today on http://forum.linearcollider.org in the "Common Simulation Framework" forum. You can find the latest version also at http://nicadd.niu.edu/~dhiman/lcd/software/simulation/simreqdoc.pdf. Many of the topics will be discussed further at the LC Software workshop next week at Argonne (http://www.hep.anl.gov/lcsw/). We intend to finalize the document over this summer. Your comments, suggestions, and questions, as a potential developer or user, are most welcome. -- On behalf of the Worldwide LC Simulation Working Group, Dhiman Chakraborty NIU/NICADD