A fiber optic connector system comprising: an elongate connector core including a front end defining a plug portion and rear end defining a cable anchoring location; a first ruggedized exterior assembly configured to be mounted over the elongate connector core, the first ruggedized exterior assembly including a first shroud configured to be mounted in sealed relation over the elongate connector core, the first shroud having a forward end that includes a first keying arrangement for rotationally keying the first shroud relative to a first ruggedized fiber optic adapter, the first ruggedized exterior assembly also including a first ruggedized fastening element for securing the first ruggedized exterior assembly to the first ruggedized fiber optic adapter; and a second ruggedized exterior assembly configured to be mounted over the elongate connector core, the second ruggedized exterior assembly including a second shroud configured to be mounted in sealed relation over the elongate connector core, the second shroud having a forward end that includes a second keying arrangement for rotationally keying the second shroud relative to a second ruggedized fiber optic adapter, the first keying arrangement having a different keying configuration than the second keying arrangement, the second ruggedized exterior assembly also including a second ruggedized fastening element for securing the second ruggedized exterior assembly to the second ruggedized fiber optic adapter, the first ruggedized fastening element having a different fastening configuration than the second ruggedized fastening element; wherein the first ruggedized exterior assembly is usable in combination with the elongate connector core to make the fiber optic connector system compatible with the first ruggedized fiber optic adapter and the second ruggedized exterior assembly is usable in combination with the elongate connector core to make the fiber optic connector system compatible with the second ruggedized fiber optic adapter. an elongate connector core including a front end defining a plug portion and rear end defining a cable anchoring location; a first ruggedized exterior assembly configured to be mounted over the elongate connector core, the first ruggedized exterior assembly including a first shroud configured to be mounted in sealed relation over the elongate connector core, the first shroud having a forward end that includes a first keying arrangement for rotationally keying the first shroud relative to a first ruggedized fiber optic adapter, the first ruggedized exterior assembly also including a first ruggedized fastening element for securing the first ruggedized exterior assembly to the first ruggedized fiber optic adapter; and a second ruggedized exterior assembly configured to be mounted over the elongate connector core, the second ruggedized exterior assembly including a second shroud configured to be mounted in sealed relation over the elongate connector core, the second shroud having a forward end that includes a second keying arrangement for rotationally keying the second shroud relative to a second ruggedized fiber optic adapter, the first keying arrangement having a different keying configuration than the second keying arrangement, the second ruggedized exterior assembly also including a second ruggedized fastening element for securing the second ruggedized exterior assembly to the second ruggedized fiber optic adapter, the first ruggedized fastening element having a different fastening configuration than the second ruggedized fastening element; wherein the first ruggedized exterior assembly is usable in combination with the elongate connector core to make the fiber optic connector system compatible with the first ruggedized fiber optic adapter and the second ruggedized exterior assembly is usable in combination with the elongate connector core to make the fiber optic connector system compatible with the second ruggedized fiber optic adapter.