Abstract: The Electron-Ion Collider (EIC) was identified in the 2015 Long-Range Plan for Nuclear Science as the highest priority for a new facility construction, with the mapping of the gluon content of nucleons and nuclei as the central goal. The EIC will collider electrons in the energy range of 5 to 15 GeV with protons (up to 250 GeV) or ions (up to 100 GeV per nucleon). The projected luminosity will be of the order of 1034 cm-2s-1 with both electrons and hadrons polarized. Construction is to begin in 2025 with operation slated to start around 2032.
After an introduction to the EIC (parameters, physics goals, and status), I will review the various EIC detector concepts being developed, with special emphasis on the TOPSiDE concept. The latter exploits recent progress in detector technology, such as imaging calorimetry, but requires also further development of existing technologies.