Two-year-old start-up Cayenne Systems Inc, a 40-man shop aiming to market object-based hypermedia software that increases user productivity, has lured away Oracle Corp’s USA group vicepresident and general manager of its direct marketing division, Thomas Siebel, to be chief executive; Marti Pozzi has been snatched from Gupta Technologies Inc where she was sales director for the slot product that is planned for the X Window System environment in the next six months.