A vibration isolator (10) with an adjustable response. A vibration isolator for isolating a vibration source from a support structure includes a base (14) in engagement with the support structure and two supports (16) connected to the base. At least one of the supports is slidably connected to the base. A flexible member (18) having a generally elongate shape and an elongate length is supported by the two supports. The flexible member is attachable to the vibration source. Each support slidably engages the flexible member such that the flexible member can move relative to each support with the support that is slidably connected to the base being moveable along the elongate length of the flexible member. The vibration isolator preferably further comprises means (42) for moving the slidably connected supports along the elongate length of the flexible member. The means for moving the slidably connected supports may be selected from a rotating shaft system, a piezoelectric actuator system, a hydraulic system, a system of racks on a common pinion, a cam bearing system, mechanical linkage systems, or mechanical cable systems. The moving means may be automated to respond to vibration occurring in the system in order to optimize the vibration isolation of the vibration isolator.