Open Source Isn't Free

Open source software has a price tag of $0 and a total cost of ownership that can dwarf commercial alternatives. The "free" in free software refers to freedom, not cost - and the industry keeps learning this lesson the hard way.

The logic is sound on paper.

I've watched organizations adopt open source with excitement, budgeting nothing for software licenses. Then they discover they've traded one cost structure for another. The money goes somewhere - from vendors to internal teams, from license fees to engineering hours.

The Costs Nobody Budgets For

When a CTO presents an open source solution, the pitch usually includes "no licensing costs" as a primary benefit. What's missing from that presentation:

• Integration engineering. Commercial software comes with support teams, documentation, and integration guides. Open source means your engineers figure it out, often through trial and error.
• Ongoing maintenance. Someone has to track updates, evaluate whether to upgrade, test compatibility, and handle breaking changes. That someone is on your payroll.
• Security monitoring. When a CVE drops for a commercial product, the vendor patches it. When a CVE drops for your open source stack, you're responsible for evaluation, patching, and deployment.
• Knowledge concentration. The engineer who set up your Kubernetes cluster becomes irreplaceable. When they leave, that knowledge leaves too.
• Opportunity cost. Every hour your senior engineers spend maintaining infrastructure is an hour not spent on product features. And each additional layer of tooling adds its own layer tax - complexity that compounds across the stack.

None of these costs appear on a software licensing line item. All of them are real.

The Maintenance Burden

Open source projects evolve on their own schedule, driven by their own priorities. Your production system sits downstream of decisions made by maintainers who don't know your use case.

A common pattern: An organization adopts an open source database. Two years later, they're three major versions behind. Each upgrade requires significant testing. They're running software with known vulnerabilities because upgrading takes too long. This is how technical debt becomes rot.

Commercial vendors want renewals - they have incentives to make upgrades painless. Open source maintainers have no such incentive. They're building for the future, not maintaining compatibility with your legacy deployment.

Security Is Your Problem Now

The Log4j vulnerability in December 2021 showed the open source security model at scale. A critical vulnerability in a logging library used by millions of applications. Maintained by a handful of volunteers. Exploited within days of disclosure.

Organizations using commercial software received patches from their vendors. Organizations running open source had to identify every affected component, evaluate the fix, test it, and deploy it themselves. Often over holiday weekends while attackers actively exploited.

The total cost of Log4j remediation for enterprises ran into billions of dollars in engineering time. As the Linux Foundation documented, none of that showed up as a "software cost."

The Support Illusion

"We'll use the community for support" sounds reasonable until you need an answer in the next four hours because production is down.

Community support works for learning and non-critical issues. It fails predictably for:

• Urgent production problems. Forum posts don't come with SLAs.
• Edge cases specific to your deployment. If nobody else has your exact configuration, nobody has solved your exact problem.
• Integration issues between components. Each project's community supports their project, not your combination of projects.

Enterprise support contracts for open source exist because organizations learned this lesson the hard way. Red Hat, Elastic, Confluent built entire businesses charging for support the "free" software doesn't include. At that point, you're paying for software. Just paying differently.

Licensing Complexity

Open source licenses are legal documents with real implications. GPL, LGPL, Apache, MIT, BSD - each has different requirements for attribution, derivative works, and redistribution.

I've seen acquisition due diligence uncover GPL-licensed code embedded in proprietary products, creating legal exposure that delayed or killed deals. I've seen compliance audits reveal license violations that required expensive remediation.

Commercial software has licensing complexity too, but it's usually explicit and negotiable. Open source licensing is implicit and non-negotiable - the terms are what they are, and violating them exposes you to litigation.

When Open Source Makes Sense

Open source isn't wrong - it's a different set of tradeoffs. It makes sense when:

• You have engineering capacity to maintain it. If you're already paying engineers who know the technology, incremental maintenance cost is manageable.
• The project is mature and stable. Linux kernel, PostgreSQL, nginx - these have decades of production use and won't surprise you.
• You need to modify the source. The freedom to change software to fit your needs is genuinely valuable for certain use cases.
• Vendor lock-in is a strategic concern. Open source provides exit options that proprietary software doesn't.
• The community is large and active. Popular projects get faster security patches and more integration options.

The calculation changes significantly when you're adopting something niche, understaffed, or rapidly evolving. The "free" licensing cost becomes very expensive very quickly in actual practice.

The Real Comparison

Total cost of ownership comparisons should include:

• Engineering time for setup and integration. Multiply hours by fully-loaded engineering cost.
• Ongoing maintenance allocation. What percentage of an engineer's time goes to keeping this running?
• Security response overhead. How many hours per year for vulnerability assessment and patching?
• Training and documentation. How long until new engineers can effectively work with this system?
• Incident response cost. When something breaks, how much does diagnosis and repair cost?
• Opportunity cost. What else could those engineering hours produce?

Run this calculation honestly and the "$0 licensing" number often becomes the most expensive option. Total cost of ownership guides show this pattern repeatedly across enterprise deployments.

The Version Upgrade Trap

Commercial vendors have incentives to make upgrades painless - they want you to stay current to reduce their support burden. Open source projects operate on different incentives. Major versions often introduce breaking changes because maintainers optimize for the future, not backward compatibility with your three-year-old deployment.

The result is organizations running increasingly outdated infrastructure. They know they should upgrade. But every evaluation reveals the upgrade requires changes to application code, deployment scripts, monitoring systems, and staff retraining. The two-week project becomes three months, then deferred because there's always something more urgent.

Meanwhile, security vulnerabilities accumulate. Eventually you're forced to upgrade - not on your schedule, but because a critical CVE forces your hand. Now you're doing an emergency upgrade under pressure, precisely when mistakes are most likely.

Before Adopting Open Source

Run through this checklist before making "free" a deciding factor:

• Calculate true TCO. Include integration, training, maintenance, security patching, and incident response—not just licensing.
• Check the bus factor. Who maintains this? One person? A foundation? A company that might deprioritize it?
• Assess your in-house expertise. Can your team maintain this without the original developers? If not, budget for training or consultants.
• Plan the upgrade path. How will you handle major version changes? Budget engineering time now.
• Evaluate vendor alternatives. Sometimes paying for support is cheaper than building expertise. Do the math.

Open source makes sense when you have the engineering capacity to own it. It doesn't make sense when you're choosing it because you can't afford the commercial alternative.

Open Source TCO Calculator

Before celebrating "$0 licensing," run this math. Use fully-loaded engineering cost (~$150-250/hour for senior engineers).

"The money goes somewhere - from vendors to internal teams, from license fees to engineering hours."