Geant3 All collaborations are using G3 to a certain extent All collaborations agree G3 is on its way out CMS and LHCb pretty much advanced in their move to G4 Atlas running their DCs with G3 Alice still based on G3 but they have an operational interface to G4 (via AliRoot) concern that a G3.5 might be in the workings

Geant4 All collaborations agree that there is no alternative to G4 (not yet, at least) LHCb and CMS already pretty much based on it, Atlas is late, Alice still support it All collaborations request that G4 be more (mostly) focussed on the LHC needs All collaborations request that the physics programme be more targeted at the LHC needs to be looked at by the HEP-URC? All collaborations complain b/c of lack of modularity (G4RunManager etc..)

Geant4 (cont’d) All collaborations regret some lack of interactive functionality (being worked around by using home-grown facilities (Iguana, Panoramix, Root…) All collaboration are trying to dismantle (to different extent) the G4 framework and use it as a real toolkit Event generation User “actions” Physics lists

Fluka All collaborations agree that: it is desirable to have an alternative to G4 the only possible alternative is (as of today) Fluka Fluka should be supported, maintained, documented and (in general) publicly available it would be desirable to have a common “Detector simulation suite” that allows one to use either G4 or Fluka as simulation engine by starting from the same geometry, event generator, user actions….

Geometrical model All collaborations have/are developing their own geometrical model, which should be used by different applications (sim, rec, vis) everybody would like to see “geometry” somehow separated from “tracking” everybody expressed interest in Rene’s geometrical model as it seems a possible unifying factor Rene’s model offers lots of facilities which are quite appealing (navigational capabilities, interactivity, etc…)