IaC Competitors

Terraform

Provider/Publisher: HashiCorp
Language: HCL (HashiCorp Configuration Language)
Purpose: Provision and manage infrastructure resources (multi-cloud and on-prem)
License: BSL 1.1 from v1.5 onwards, previously MPL 2.0
State Management: Uses a single state file (can be stored locally or remotely)

Pulumi

Provider/Publisher: Pulumi Corp.
Language: Multiple programming languages (TypeScript, Python, Go, C#, Java, etc.)
Purpose: Provision and manage infrastructure via an “Infrastructure as Software” approach
License: Apache License 2.0 (Community Edition); additional commercial offerings
State Management: Managed in the Pulumi Service (SaaS) or self-hosted (e.g., AWS S3, Git-based, etc.)

AWS CloudFormation

Provider/Publisher: Amazon Web Services (AWS)
Language: JSON or YAML templates
Purpose: Provision and manage AWS resources (primarily focused on AWS ecosystem)
License: Proprietary (AWS service) – no additional cost for CloudFormation itself, but AWS usage fees apply
State Management: Handled by AWS via “Stacks” stored within the CloudFormation service

OpenTofu

Provider/Publisher: Community-driven project (hosted under the Linux Foundation)
Language: HCL (HashiCorp Configuration Language) / JSON
Purpose: Provision and manage infrastructure resources across multiple providers; a fully open-source fork of Terraform
License: MPL 2.0 (no BSL restrictions)
State Management: Utilizes a state file (local or remote), analogous to Terraform

Key Differences

Aspect	Terraform	Pulumi	AWS CloudFormations	OpenTofu
Framework	Standalone CLI tool	CLI + optinal hosted services	AWS-native service for provisioning resources	Standalone CLI tool, community driven Terraform fork
Configuration Language	HCL/JSON	Multiply languages (TypeScript/JavaScript, Python, Go, C#, Java, F#, YAML)	YAML/JSON	HCL/JSON
Secret Management	Secrets are stored in a seperate product(Vault)	Secrets are encrypted in transit and in the state file	Deeply integrated in AWS Secres Manager and AWS SSM Parameter Store	Similar to terraform, no built-in store, recommended in a seperate product(vault)
State Handling	Central state file, no state encryption, supports remote backends (e.g S3)	State managed in Pulumi Service or self-hosted (e.g S3)	AWS manages state internally (no local files)	Central state file, supports remote backends, just like Terraform but has his own state encryption
Extensibility	Providers & Modules Ecosystem	Native providers(e.g AWS,Azure,GCP) + Terraform providers via Pulumi Terraform Bridge	Supports macros, nested stacks, and custom resources (AWS scope)	Providers and modules (mirrowing Terraform ecosystem)
Execution Model	CLI, imperative runs on command	Imperative CLI approach	Declarative stack-based, changes orchestrated by AWS	Imperative runs on command
Community Support	Large established community, considered a standard in IaC	Growing community	Large AWS user base, official AWS support	New Project (2023+), quickly growing
Setup	Download Binary, add to PATH	Install CLI, or sign up for Pulumi Service	No local setup needed (AWS console or CLI), part of AWS ecosystem	Download Binary, add to PATH
Learning Curve	Straightforward for entry-level IaC, many resources and documentations available, can be complex with advanced patterns	Familiar to developers comfortable with code, lesser documentation, but still growing	Easier for AWS users, can be complex, good AWS documentations	Download Binary, add to PATH
Licensing	BSL 1.1 from v1.5 onwards, previously MPL 2.0	Apache License 2.0	Proprietary (AWS Service), AWS resource usage fees	Mozilla Public License 2.0, no BSL restrictions

Terraform vs Pulumi differences

Terraform and Pulumi Language & Configurations difference:
Terraform configuration example file to create Azure Resource Group with HCL language.
Same configuration file written in C# for Azure Resources
Terraform typically stores its state in a local terraform.tfstate file (though best practice is to use a remote backend like Azure Blob or S3 for collaboration).

Whereas Pulumi stores its state in the Pulumi Cloud by default, enabling “diff”-based reviews through its use of common development languages. It allows state storage in S3, Azure Blob or local files, similar to Terraform.
When it comes to reusability, Terraform encourages the use of modules for organizing and sharing configurations, while Pulumi relies on standard programming constructs (functions, classes, packages) to enable code reuse, reflecting each tool’s approach to Infrastructure as Code.
While Terraform has no build in secret encryption and needs external services like S3 for it, Pulumi has a build-in secret encryption which is stored securely in the Pulumi state. It allows also external services if wanted.
Basic CLI differences: The command line interface to Terraform is the terraform command, which accepts a number of subcommands such as terraform init or terraform plan.

For Pulumi it is similar how the CLI works. To start working for Pulumi the command pulumi must be executed:

Other main commands:

Terraform vs OpenTofu differences

Since OpenTofu is fork of terraform and uses also the terraform eco system there are only few differences:

OpenTofu Project was launched as a free alternative to Terraform after Terraform changed to BSL license. It mirrors terraform as fork but has not the BSL license restrictions.
While terraform is controlled by HashiCorp,OpenTofu's development is completly Community-driven. It has his independent roadmap and its aiming for a transparent model.
For Command & Syntax, OpenTofu uses the opentofu CLI but mirrors Terraform syntax and modules
OpenTofu has its own encryption of the status files, which is not the case with Terraform.

Here a minimal configuration how to use the encryption:

The OpenTofu looks exactly like terraform, because they both using HCL Language.

Terraform vs AWS CloudFormations differences

CloudFormations is limited to AWS-Only where Terraform supports multiple providers e.g AWS, Azure, GCP etc.
Terraform uses HashiCorp Configuration Language (HCL), which is more expressive and allows custom modules, whereas CloudFormation relies on JSON/YAML, which can be verbose and harder to manage at scale.
Terraform maintains a state file (terraform.tfstate), allowing better tracking of changes but requiring manual management, while CloudFormation inherently manages state within AWS without needing external storage.

AWS Cloud Formations doesnt need an extra, you use the AWS CLI or the AWS Console for it.

To create a stack from a template in the beginning:

aws cloudformation create-stack --stack-name myteststack 
--template-body file://sampletemplate.json 
--parameters ParameterKey=KeyPairName,ParameterValue=TestKey ParameterKey=SubnetIDs,ParameterValue=SubnetID1\\,SubnetID2

For deploying a stack:

aws cloudformation deploy --stack-name myteststack \
  --template /path_to_template/my-template.json \
  --parameter-overrides Key1=Value1 Key2=Value2

To remove an existing stack and all associated resources:

aws cloudformation delete-stack \
    --stack-name my-stack

Quick Pointers for Leaning Terraform

If you want getting started and dive into advanced terraform operations, the registry and the official HashiCorp tutorials are excellent resources to help you master Terraform.

Official Registry
- registry.terraform.io is the central place to discover and share Terraform providers, modules, policies, and more.
- You can search by cloud provider (AWS, Azure, GCP) or functionality (e.g., Kubernetes, GitHub).
Tutorials & Guides
- developer.hashicorp.com/terraform/tutorials provides step-by-step tutorials, from beginner-level introductions to more advanced topics like modules and remote state.
Providers
- registry.terraform.io/browse/providers lists all official and community-managed providers. Each provider page includes documentation on usage, resource types, and examples.
Modules
- registry.terraform.io/browse/modules is where you can find reusable configurations (modules) for common tasks (e.g., VPC creation, AWS EC2 setup).
- Download or reference modules directly in your .tf files to keep code DRY (Don’t Repeat Yourself).
Policies:
- registry.terraform.io/browse/policies highlights policies that can be enforced to meet compliance or security requirements, often used with Terraform Enterprise or Terraform Cloud.