Srikanth Sharma
September 19, 2025
5 Minutes read
The Right IaC Tool for Open Source & Multi-Cloud Agility: OpenTofu, Pulumi, or Crossplane?
In today’s cloud-first world, managing infrastructure manually is no longer sustainable. As organizations expand across diverse environments and multiple cloud providers, the complexity of provisioning, managing, and maintaining cloud resources grows exponentially. This is where Infrastructure as Code (IaC) becomes a game-changer. By treating infrastructure the same way, we treat application code—automated, version-controlled, and portable—IaC enables teams to deliver faster, safer, and more reliable infrastructure at scale.
Key Drivers Behind IaC Adoption
- Scalability: Cloud environments evolve rapidly, and workloads often need to scale up or down within minutes. IaC enables rapid resource provisioning at scale, ensuring agility without compromising reliability.
- Consistency: Declarative code reduces the risks of manual intervention and prevents configuration drift, ensuring development, testing, and production environments remain identical.
- Collaboration: With infrastructure defined as code, teams can use version control systems like Git, enabling peer reviews, rollbacks, and seamless collaboration across development, operations, and security.
- Multi-cloud and Hybrid Cloud: Modern enterprises rarely rely on a single provider. IaC abstracts away cloud-specific complexities, enabling portable and reusable infrastructure definitions across AWS, Azure, GCP, and on-premises environments.
- DevOps & GitOps Alignment: IaC forms the backbone of CI/CD pipelines and GitOps practices, ensuring infrastructure changes are tested, reviewed, and deployed with the same rigor as application code.
- Cost & Performance Optimization: With IaC, infrastructure lifecycles can be automated to optimize spend, such as spinning up ephemeral environments on-demand, auto-scaling workloads, and enforcing policies for cost-efficient operations.
Key IaC Tools & Ecosystem
Here are some of the most widely adopted Infrastructure as Code (IaC) tools and their highlights:
| Tool | Highlights |
| Terraform / OpenTofu | Recognized leaders in multi-cloud IaC. Terraform (now under a Business Source License) and OpenTofu (its open-source fork) power large-scale automation with broad ecosystem support. Recent adoption trends show OpenTofu gaining traction, with around 20% of new projects opting for it. |
| Pulumi | Enables IaC using general-purpose programming languages such as Python, TypeScript, and Go. Key strengths include real-time previews, automation APIs, and growing support for governance and policy enforcement, including AI-driven tooling. |
| Cloud Provider-Native Tools | AWS CloudFormation, Azure Resource Manager, and GCP Deployment Manager continue to serve cloud-specific use cases with deep integration and compliance capabilities. |
| Cloud Development Kit (CDK) | A developer-friendly IaC framework that supports multiple cloud providers and programming languages. It serves as a bridge between application code and infrastructure design. |
| Ansible, Puppet, Chef | Although traditionally designed for configuration management, these tools continue to play a role in IaC workflows, particularly in hybrid and on-premises environments. |
Market Insights
- Scale & Growth: The IaC market is expanding rapidly, with projections estimating growth to ~$4–9B over the next decade.
- Tool Leaders:
- Terraform / OpenTofu remain dominant for multi-cloud deployments.
- Pulumi is gaining momentum, offering a modern, developer-centric approach to IaC.
- Cloud-native tools such as CloudFormation and CDK are still preferred for provider-specific use cases.
- Future Trends:
- Multi-tool adoption enabled by orchestration, cataloging, and observability.
- GitOps, policy governance, and AI-driven workflows shaping next-gen IaC.
- Increased developer empowerment via self-service infrastructure platforms.
Evaluation of IaC Tools
With HashiCorp’s Terraform shifting to a Business Source License under IBM, enterprises and DevOps teams face critical questions about long-term sustainability, cloud neutrality, and tooling freedom. Below is an evaluation of the top three open-source, cloud-agnostic IaC tools, based on the following selection criteria:
- Fully open source with permissive licensing
- Cloud-agnostic with support for AWS, Azure, and GCP
- Actively maintained and backed by a strong community
- Capable of managing complex infrastructure
Pulumi
Pulumi uses general-purpose programming languages (TypeScript, Python, Go, C#, Java) instead of HCL to define infrastructure. It supports AWS, Azure, GCP, Kubernetes, and many other platforms.
Pros
- General-purpose languages: Can use loops, conditionals, functions, and package ecosystems
- Multi-cloud ready: Native SDKs for AWS, Azure, GCP, Kubernetes, and 50+ providers
- Strong developer experience: IDE autocomplete, type checking, and debugging
- State management flexibility: Can store state locally, in Pulumi Cloud, or in self-hosted backends
- Rich ecosystem: Integrates well with CI/CD pipelines
Cons
- Learning curve: Requires programming language skills beyond HCL
- Smaller community than Terraform: Though growing fast
- Pulumi cloud optional SaaS lock-in risk: Free tier available, but some advanced features are commercial
Feature Comparison – Terraform vs Pulumi
The table below summarizes the key differences between Terraform and Pulumi:
| Feature | Terraform (HCL) | Pulumi (Code-based IaC) |
| Language | HCL (domain-specific, declarative) | General-purpose languages (TS, Python, Go, C#, Java) |
| Learning Curve | Easier for ops teams | Familiar to developers, requires programming knowledge |
| Abstraction | Declarative infrastructure only | Imperative + declarative (can use loops, conditionals, APIs) |
| Providers | Wide ecosystem (AWS, Azure, GCP, etc.) | Same ecosystem, Pulumi maps to Terraform providers |
| State Management | Local/remote (S3, GCS, AzureRM, etc.) | Pulumi Service (managed) or self-hosted backend |
| Ecosystem & Community | Larger, mature | Growing rapidly, dev-friendly |
| Migration Effort | Native | Moderate – requires rewriting HCL into chosen language |
Crossplane
Crossplane extends Kubernetes into a universal control plane for managing cloud resources. Using Kubernetes Custom Resource Definitions (CRDs), it enables IaC through YAML manifests while aligning closely with GitOps workflows.
Pros
- Kubernetes-native: Ideal for teams already invested in K8s
- Cloud-agnostic orchestration: Manage AWS, Azure, GCP, and on-prem resources via Kubernetes APIs
- GitOps-friendly: Integrates seamlessly with tools like ArgoCD, Flux, etc.
- Composable: Supports higher-level abstractions through “Compositions” to hide provider complexity
- No separate state management: Kubernetes handles resource states
Cons
- Steep learning curve: Requires strong Kubernetes expertise
- Verbose YAML: Large configurations can become unwieldy
- Non-Kubernetes overhead: Adds complexity if Kubernetes is not already in use
- Provider maturity: Some cloud providers are still catching up to Terraform’s ecosystem
Feature Comparison – Terraform vs Crossplane
The following table compares Terraform and Crossplane across key features:
| Feature | Terraform (HCL) | Crossplane (Kubernetes CRDs) |
| Language | HCL (HashiCorp Configuration Language) | YAML (Kubernetes-style manifests) |
| Execution | CLI-driven (terraform apply) | Runs inside Kubernetes via controllers |
| State Management | Local/remote (S3, GCS, etc.) | Kubernetes etcd (state managed by Kubernetes) |
| Extensibility | Modules + Providers | Compositions + Custom CRDs |
| Target Users | Infra/DevOps teams | Platform Engineering / GitOps teams |
| Multi-cloud | Supported via providers | Native multi-cloud via Kubernetes CRDs |
| Integration | Works standalone | GitOps-native (ArgoCD, Flux), fits K8s ecosystem |
| Migration Effort | Native HCL → HCL | High – requires rewriting Terraform configs into Kubernetes CRDs |
OpenTofu
OpenTofu is the open-source, community-driven fork of Terraform, created after HashiCorp’s shift to the Business Source License. It remains fully HCL-compatible and backward-compatible with Terraform.
Pros
- Free & open source: No license concerns
- Drop-in Terraform replacement: 100% HCL compatibility.
- Large ecosystem: Can reuse Terraform providers and modules
- Minimal migration effort: Minimal or no refactoring needed
- Active open governance: CNCF sandbox project
Cons
- Limited innovation (for now): Current focus is on stability and parity with Terraform
- Ecosystem dependency: Still tied to Terraform’s provider and module ecosystem
- HCL limitations: Less expressive than general-purpose programming languages.
- State management unchanged: Remains manual, similar to Terraform.
Feature Comparison – Terraform vs OpenTofu
Here’s a side-by-side comparison of Terraform and OpenTofu:
| Feature | Terraform | OpenTofu |
| Syntax / HCL | HCL (HashiCorp Configuration Language) | 100% compatible HCL (same syntax) |
| Providers | HashiCorp + community registry | Uses same registry; future open forks may appear |
| Licensing | BSL (Business Source License) by IBM/HashiCorp | MPL 2.0 (truly open-source & free) |
| State Management | Local, remote (S3, GCS, AzureRM, etc.) | Same remote state backends supported |
| CLI Commands | terraform init/plan/apply/destroy | tofu init/plan/apply/destroy |
| Ecosystem | Larger, mature ecosystem | Rapidly growing, Terraform configs work without changes |
| Migration Effort | N/A (native) | Very low — mostly rename binaries (terraform → tofu) |
Comparison Matrix
Here’s a quick comparison of the three open-source IaC tools – Pulumi, Crossplane, and OpenTofu:
| Feature/Criteria | Pulumi | Crossplane | OpenTofu |
| Language | TypeScript, Python, Go, C#, Java | YAML (Kubernetes CRDs) | HCL (Terraform-compatible) |
| Cloud Support | AWS, Azure, GCP, K8s, many others | AWS, Azure, GCP, on-prem (via K8s) | AWS, Azure, GCP, many others |
| State Management | Pulumi backend or self-hosted | Kubernetes API (no separate state files) | Local, remote, or Terraform Cloud |
| Learning Curve | Medium (needs coding skills) | High (needs K8s + CRD knowledge) | Low (same as Terraform) |
| Best Fit For | Developer-focused IaC, app + infra code | GitOps & Kubernetes-centric orgs | Organizations seeking a Terraform-compatible tool |
| Open Source | Yes | Yes | Yes |
| Maturity | Mature, growing fast | Rapidly maturing | Stable (inherits Terraform maturity) |
| License | Apache 2.0 | Apache 2.0 | Mozilla Public License |
| Extensibility | High | High | Medium |
| Ease of Migration | Medium (via tf2pulumi) | Medium (manual mapping) | High (mostly drop-in) |
Conclusion
The right open-source, cloud-agnostic alternative to Terraform in 2025 ultimately depends on an organization’s existing skill sets, operational priorities, and long-term strategy.
For ease of adoption, OpenTofu stands out as the most straightforward choice. Its complete backward compatibility with Terraform’s HCL syntax allows teams to migrate with minimal retraining or tooling changes, making it ideal for organizations that want to avoid licensing restrictions while preserving existing workflows.
In terms of performance, all three tools can efficiently manage large-scale deployments across AWS, Azure, and GCP. However, Pulumi has an edge in developer-centric environments due to its use of general-purpose languages, strong type safety, and seamless integration with modern CI/CD pipelines—reducing errors and accelerating delivery in complex setups.
When considering migration effort, OpenTofu again leads, as existing Terraform configurations can be imported and executed with virtually no changes. Pulumi requires more refactoring since HCL must be translated into a programming language, but it pays off in flexibility for long-term scaling. Crossplane demands the highest migration effort because it requires rethinking infrastructure definitions such as Kubernetes Custom Resources — a move that can yield powerful GitOps-driven automation, but at a higher initial adoption cost.
Final Recommendations
For organizations prioritizing minimal disruption and the fastest migration path, OpenTofu is the most pragmatic choice. It preserves existing Terraform workflows, leverages the same provider ecosystem, and removes licensing restrictions. For teams seeking more advanced programmability and tighter integration between infrastructure and application code, Pulumi is the better long-term bet. Crossplane should be considered by cloud-native organizations deeply invested in Kubernetes and GitOps practices.
About ACL Digital
ACL Digital partners with enterprises to simplify cloud adoption and modernize infrastructure through DevOps, Infrastructure as Code (IaC), and automation. With deep expertise across AWS, Azure, GCP, and Kubernetes, we help organizations evaluate, select, and implement the right IaC tools—whether OpenTofu, Pulumi, or Crossplane, based on their business and technical needs. Our experience spans cloud migration, multi-cloud architecture, and large-scale platform engineering, enabling enterprises to achieve agility, scalability, and operational efficiency.
Choosing between OpenTofu, Pulumi, or Crossplane? Let our experts guide you to the right decision for your enterprise. Contact us
