# HCL Changelog ## v2.0.0 (Unreleased) Initial release of HCL 2, which is a new implementating combining the HCL 1 language with the HIL expression language to produce a single language supporting both nested configuration structures and arbitrary expressions. HCL 2 has an entirely new Go library API and so is not a drop-in upgrade relative to HCL 1. It's possible to import both versions of HCL into a single program using Go's _semantic import versioning_ mechanism: ``` import ( hcl1 "github.com/hashicorp/hcl" hcl2 "github.com/hashicorp/hcl/v2" ) ``` --- Prior to v2.0.0 there was not a curated changelog. Consult the git history for information on the changes to HCL 1.