Each circle could touch or overlap with adjacent circles (a phenomenon called 'osculation').
operating system | Super Nintendo Entertainment System | Nintendo Entertainment System | Android (operating system) | Global Positioning System | Solar System | X Window System | Korean Broadcasting System | System of a Down | Domain Name System | Seoul Broadcasting System | North Carolina Community College System | Mutual Broadcasting System | Bulletin board system | system | Turner Broadcasting System | Program and System Information Protocol | Geographic information system | Ubuntu (operating system) | Tokyo Broadcasting System | Federal Reserve System | Youth system | Embedded system | solar system | Seigneurial system of New France | Interstate Highway System | Fedora (operating system) | Trans-Alaska Pipeline System | Network File System (protocol) | English football league system |