Terraform vs Pulumi
A comparison of Terraform, HashiCorp's (now IBM's) infrastructure-as-code tool using HCL, and Pulumi, which lets teams define infrastructure in general-purpose programming languages like TypeScript, Python, and Go.
Quick Answer
Terraform remains the market leader with the largest provider ecosystem and deepest institutional adoption, now under IBM ownership following its 2025 acquisition of HashiCorp; Pulumi lets teams write infrastructure in real programming languages they already know, trading some ecosystem breadth for full language expressiveness and easier integration with existing application code.
Reviewed by TechLogHub Engineering Team. Last updated September 20, 2026. Updated for IBM's February 2025 acquisition of HashiCorp and the continued three-way IaC landscape alongside OpenTofu as of 2026.
| Feature |  Terraform |  Pulumi |
|---|---|---|
| Configuration Language | HCL (HashiCorp Configuration Language) | TypeScript, Python, Go, C#, Java (general-purpose) |
| License | Business Source License (BSL 1.1) | Open source (Apache 2.0 core) |
| Provider Count | 4,800+ | Smaller than Terraform, covers all major clouds |
| Market Share | ~32.8% (market leader) | Growing, smaller than Terraform |
| Owner/Steward | IBM (since February 2025 acquisition) | Pulumi Corporation |
| Key Features | HCP Terraform, Sentinel, Stacks, ephemeral resources | Full language expressiveness, native IDE support |
Terraform
The market-leading infrastructure-as-code tool, using its own declarative HashiCorp Configuration Language (HCL), now owned by IBM following its February 2025 acquisition of HashiCorp, with the largest provider ecosystem in the IaC space.
Pros
- Largest provider ecosystem in infrastructure as code — 4,800+ providers covering virtually every cloud and SaaS platform
- Market leader with roughly 32.8% market share and the deepest institutional and community adoption
- HCL's declarative, purpose-built syntax is relatively approachable to learn even for those without a programming background
- Mature tooling ecosystem: HCP Terraform, Sentinel policy-as-code, and the newer Stacks feature for managing infrastructure at scale
- Extensive existing documentation, tutorials, and community modules given its decade-long head start
Cons
- Licensed under the Business Source License (BSL) since August 2023, a source-available rather than fully open-source license, which some organizations consider a licensing risk
- Now owned by IBM following its $6.4 billion acquisition of HashiCorp in February 2025, adding a new layer of corporate direction uncertainty for some teams
- HCL's domain-specific language, while approachable, lacks the full expressiveness of a general-purpose programming language (loops, conditionals, and abstractions require workarounds)
- Terraform Cloud's free tier changes have pushed some teams toward alternatives
Best For
Teams that want the largest possible provider ecosystem and the deepest institutional track record, and are comfortable with (or unconcerned by) the BSL license and IBM's ownership of HashiCorp.
Pulumi
An infrastructure-as-code platform that lets teams define infrastructure using general-purpose programming languages — TypeScript, Python, Go, C#, and Java — rather than a dedicated configuration language.
Pros
- Infrastructure defined in real programming languages your team likely already knows, with full access to loops, conditionals, functions, and abstractions
- Easier integration with existing application codebases and CI/CD pipelines already built around the same language
- No licensing controversy comparable to Terraform's BSL change — Pulumi's core is open source
- Full IDE support (autocomplete, type checking, refactoring tools) that a general-purpose language provides, unlike a bespoke DSL
- Growing rapidly as an alternative specifically for teams wanting to avoid Terraform's licensing situation or DSL limitations
Cons
- Smaller provider ecosystem than Terraform's 4,800+ providers, though it covers all major clouds
- Smaller overall market share and community size, meaning fewer existing tutorials and troubleshooting resources for edge cases
- Requires genuine programming language proficiency, which can be a steeper barrier for infrastructure-focused teams less comfortable writing full programs
- The power of a general-purpose language cuts both ways — it's possible to write infrastructure code that's harder to reason about than Terraform's more constrained, declarative HCL
Best For
Teams that want infrastructure defined in the same programming languages as their application code, value full language expressiveness over a purpose-built DSL, and want to avoid Terraform's BSL licensing situation.
The 2023 License Change That Reshaped the IaC Landscape
In August 2023, HashiCorp changed Terraform's license from the permissive, fully open-source Mozilla Public License 2.0 to the more restrictive Business Source License (BSL) 1.1, primarily to prevent competitors from offering Terraform as a competing managed service without a commercial agreement. This single decision reshaped the entire infrastructure-as-code landscape: it directly triggered the OpenTofu fork within weeks, and it accelerated interest in Pulumi as an alternative for teams wanting to avoid the licensing uncertainty entirely, even though Pulumi's core motivation (general-purpose language support) predates the license change.
IBM's Acquisition Adds Another Layer of Consideration
IBM completed its $6.4 billion acquisition of HashiCorp in February 2025, meaning Terraform's future direction is now shaped by IBM's broader enterprise strategy rather than an independent HashiCorp. For teams evaluating long-term platform risk, this is worth factoring in alongside the BSL licensing question — some organizations view IBM's backing as a stabilizing force, while others see it as adding a new layer of corporate priorities that may not align with the open-source community's interests.
DSL vs General-Purpose Language: A Genuine Trade-off, Not Just Preference
Terraform's HCL is a purpose-built declarative language, which makes infrastructure definitions relatively easy to read and reason about, but its limited expressiveness (workarounds needed for loops, conditionals, and complex logic) can become genuinely restrictive for sophisticated infrastructure patterns. Pulumi's use of general-purpose languages removes those restrictions entirely, but that same power means it's possible to write infrastructure code that's harder to statically reason about or that introduces bugs a more constrained DSL would have prevented by design. Neither trade-off is objectively correct — it depends on how much programmatic flexibility your infrastructure genuinely needs.
Provider Ecosystem Breadth Still Favors Terraform Significantly
Terraform's decade-long head start shows most clearly in its provider ecosystem — over 4,800 providers covering virtually every cloud platform, SaaS tool, and infrastructure service imaginable. Pulumi covers all major cloud providers thoroughly, and can also leverage Terraform's provider ecosystem via a bridge layer in many cases, but for genuinely niche or newer infrastructure providers, Terraform's native ecosystem breadth remains a real practical advantage.
Verdict
Choose Terraform if you want the largest provider ecosystem and deepest institutional track record, and aren't concerned by its BSL licensing or IBM's ownership of HashiCorp — it remains the clear market leader. Choose Pulumi if you want infrastructure defined in the same general-purpose programming language your team already writes application code in, value full language expressiveness, and want to sidestep Terraform's licensing situation entirely. If licensing concerns specifically (rather than language preference) are your main driver, also consider OpenTofu — see our dedicated OpenTofu vs Terraform comparison.