| IT-System | IT system |
| Typsystem | type system |
| Exosystem | exosystem |
| Leitsystem | distributed control system |
| Subsystem | subsystem |
| System | system structure |
| Tonsystem | pitch space |
| Ökosystem | ecosystem |
| Dateisystem | file system |
| Notensystem | stave |
| Untersystem | sub-system |
| Wahlsystem | voting system |
| Binärsystem | binary system |
| Immunsystem | immune system |
| Oktalsystem | octal numeral system |
| Sternsystem | star system |
| K.-o.-System | knockout system |
| ich-synton | egosyntonic |
| Justizsystem | judiciary |
| Soundsystem | sound system |