# OpenHCL

OpenHCL is an execution environment which runs OpenVMM as a **paravisor**.

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To learn more about OpenHCL's architecture, please refer to
[OpenHCL Architecture](../reference/architecture/openhcl.md).

```admonish note
_Note:_ As you explore the OpenVMM repo, you may find references to the term
**Underhill**.

Underhill was the former codename for OpenHCL, so whenever you see the term
"Underhill", you can treat it as synonymous to "OpenHCL".

We are actively migrating existing code and docs away from using the term
"Underhill".
```
