Spacelift

Terraform

hashicorp/terraform

Popular

Declarative IaC with the largest provider ecosystem; owned by IBM (HashiCorp) and BSL-licensed since 2023.

OpenTofu

opentofu/opentofu

Rising

Open-source (MPL) Linux Foundation fork of Terraform; drop-in compatible, adds state encryption and more.

Pulumi

pulumi/pulumi

IaC in TypeScript, Python, Go, C# or Java instead of a DSL, with managed state, policies and secrets.

AWS CDK

aws/aws-cdk

Popular

Defines AWS infrastructure in TypeScript, Python, Java or C# and synthesizes it to CloudFormation.

AWS CloudFormation

aws.amazon.com

AWS's native declarative IaC service using JSON/YAML templates with managed state and drift detection.

Bicep

Azure/bicep

Azure's concise DSL for deploying resources that compiles to ARM templates; first-party Azure IaC.

Crossplane

crossplane/crossplane

Kubernetes control plane that provisions and composes cloud resources through custom APIs (CRDs).

Terragrunt

gruntwork-io/terragrunt

Thin wrapper for Terraform/OpenTofu that keeps multi-environment configs DRY and orchestrates stacks.

Atlantis

runatlantis/atlantis

Self-hosted pull-request automation that runs Terraform/OpenTofu plan and apply from PR comments.