Heavy-ion microlithography can produce microstructures in a variety of materials, comprising many different elementary forms of etched ion tracks. It has several unique characteristics that enable individual ions to produce high-aspect-ratio features. Further development is needed to give better hit detection by covering poor secondary-electron emitters, such as polycarbonate, with thin gold to reduce the number of fake hits. Wether coincidence techniques can lead to more reliable hit detection remains to be demonstrated. The economic viability of single-ion micromechanics has not yet been shown, however, and will depend on the fabrication of unique and valuable microstructures. The real value so far has been in the development of the tools described in this article, which have enabled us to branch into other valuable activities including imaging of radiation-sensitive sites in integrated circuits (similar to work described in the article by Schöne and Jamieson) and single-cell irradiation in biology. Other unforeseen developments have arisen from our development of heavy-ion microlithography. For example, the scanning strategy used to deliver a specific number of ions per position within the scanned area has been adapted to a relativistic ion beam to write extremely complex and exact dose patterns into a tumor volume in an advanced tumor therapy installation with heavy ions.