The science potential of xray storage rings would be largely enhanced if electron pulses with smaller emittances, i.e. reduced cross section, and with shorter pulse length could be produced. Energy Recovery Linacs (ERLs) have the potential to provide the required unprecedented beam properties, and advantages of ERLs as drivers of x-ray sources will be explained. The status of plans for ERL xray facilities will be described, some of which are extensions of existing accelerators, some are green-field designs.
