| Abbreviation | Definition |
|---|---|
| UIST | User Interface Software and Technology |
| UIU | Universal Imaging Utility |
| UIUX | User Interface and User Experience |
| UIX | User Interface and Executive |
| UIX | User Interface Xml |
| UJD | Unified JAVA Desktop |
| UJM | Universal Job Management |
| UKS | Universal Knowledge Software |
| UKT | User Kernel Thread |
| UL | Universal Locator |
| UL | Up Left |
| ULCK | Urban Legend Combat Kit |
| ULK | Understanding the Linux Kernel |
| ULK3 | Understanding the Linux Kernel, 3rd Edition |
| ULS | Unified Logging Service |
| ULW | Universal Latent Workstation |
| UMB | Upper Memory Block |
| UMC | User Meta Certificate |
| UME | Unix Made Easy |
| UMLSKS | Unified Medical Language System Knowledge Source Server |