Imaging X-ray mirrors has been developed in Czechoslovakia since 1970 by a way of two different replica technologies based on galvanoplastics and reactoplastics as a natural part of Czechoslovak X-ray astronomy program. Until' now about 30 mirrors with diameters between 1.7 and 24 cm were manufactured. Seven mirrors were flown in space experiments. The new technology used since 1981 allows to produce light-weight X-ray mirrors at relatively very low cost.The technology offers interesting possibilities in construction of (i) large arrays of identical optical systems, (ii) very small (microscopic) mirrors and (iii) lobster-eye type optics. Advantages and drawbacks of replica technology are discussed.