| Abk. | Bedeutung | Kontext |
| J | Japan | Autokennzeichen |
| JDBC | Java Database Connectivity | |
| JDK | Java Development Kit | |
| JEDEC | Joint Electronic Devices Engineering Council | |
| JET | Joint Engine Technology | Microsoft |
| JFC | Java Foundation Classes | |
| JIT | Java Informations Tage | |
| JIT | Just in time | |
| JMLC | Joint Modular Languages Conference | |
| JPEG | Joint Photographic Experts Group | |
| JSP | Java Server Pages | |
| JZ | Juristenzeitung | Zeitschrift |