- H Hexadecimal
- HALs Hardware Abstraction Layers
- HCI Human-Computer Interaction
- HCSS High Capacity Storage System
- HDLC High-level Data Link Control
- HDTV High-Definition TeleVision
- HFC Hybrid Fiber Coax
- hhos ha ha only serious
- HLLAPI High Level Language Applications Programming Interface
- HMA High Memory Area
- HMD Head-Mounted Display
- HMOS High-speed Metal Oxide Semiconductor
- HP Hewlett-Packard
- HPCA High Performance Computing Act
- HPCC High Performance Computing and Communication
- HPFS High-Performance File System
- HPPCL Hewlett-Packard Printer Command Language
- HPPI High Performance Parallel Interface
- HS High Speed
- HSM Hierarchical Storage Management
- HSV Hue Saturation and Value
- HTML HyperText Markup Language
- HTTP HyperText Transfer Protocol
- HYTELNET HYpertext Browser for TELNET-accessible sites
- Hz Herz