The recent progress in the fabrication of GeOI substrates and devices is reviewed. Improvements have been made in threading dislocation density, Ge-buried oxide interface passivation, device performance. The potential of various co-integration schemes (lateral and vertical) has been illustrated as alternatives to the fabrication of n-type germanium channel devices. GeOI is also shown to be a versatile platform for the monolithic integration of Si and III-V devices and tunneling field effect transistors.