HCL (HashiCorp Configuration Language) is a configuration language designed to be both human and machine-readable for use in infrastructure automation. It is a data serialization language designed to help developers write and deploy cloud resources across multiple platforms. HCL was designed to be both simple enough for humans to read and easy for computers to parse. It was created by HashiCorp and released in April 2016 to replace their previously used JSON-based configuration language. HCL has a syntax that is similar to JSON and supports a variety of scalar and data structures, such as booleans, integers, strings, lists, maps, and objects. It is also extendable and can accept custom data types. HCL is used as the configuration language for many HashiCorp tools, including Terraform, Vault, Nomad, and Consul.