| Abbreviation | Definition |
|---|---|
| HCL | Hindustan Computers Limited |
| HCM | Host Connectivity Manager (Linux) |
| HCPC | Healthcare Common Procedure Coding |
| HCS | Health Care Software |
| HCS | Herp Care Software |
| HCS | Highway Capacity Software |
| HCSC | Horse Cents Software Company |
| HCSS | High Confidence Software and Systems |
| HCT | Hardware Compatiblity Test |
| HD | Harmonised Document |
| HDAS | Hydrographic Data Acquisition System |
| HDCP | High Definition Content Protocol |
| HDCR | Hyp Debug Control Register |
| HDFS | Hadoop Distributed File System |
| HDI | Hitachi Debugging Interface |
| HDL | High-level Description Language |
| HDMI | Hardly Demonstrative of a Modern Interface |
| HDO | High Density Overlay |
| HDP | heuristic dynamic programming |
| HDP | Hortonworks Data Platform |