There are many inventions described and illustrated herein. In one aspect, the present invention is directed to a compensated microelectromechanical oscillator, having a microelectromechanical resonator that generates an output signal and frequency adjustment circuitry, coupled to the microelectromechanical resonator to receive the output signal of the microelectromechanical resonator and, in response to a set of values, to generate an output signal having second frequency. In one embodiment, the values may be determined using the frequency of the output signal of the microelectromechanical resonator, which depends on the operating temperature of the microelectromechanical resonator and/or manufacturing variations of the microelectromechanical resonator. In one embodiment, the frequency adjustment circuitry may include frequency multiplier circuitry, for example, PLLs, DLLs, digital/frequency synthesizers and/or FLLs, as well as any combinations and permutations thereof. The frequency adjustment circuitry, in addition or in lieu thereof, may include frequency divider circuitry, for example, DLLS, digital/frequency synthesizers (for example, DDS) and/or FLLs, as well as any combinations and permutations thereof.