Azul.

A server farm, somewhere, at 2 a.m.

Somewhere right now, a trade is clearing in microseconds. A flight is being priced. A payroll run for half a million people is grinding through the night. None of these systems carry Azul's name. All of them are running on it.

Azul makes Java runtimes - the unglamorous engine block underneath an enormous slice of enterprise software. It is the largest independent Java vendor on earth and one of the biggest contributors to OpenJDK, the open-source heart of the language. It is also, charmingly, the company most often confused with a Brazilian airline.

The work is invisible by design. When Azul does its job, nothing happens: no pause, no outage, no surprise audit. That is a difficult thing to put on a billboard, which is part of why you have never heard of a company that quietly underpins roughly a third of the Fortune 100.

Java is everywhere. So is the bill.

Here is the problem Azul exists to solve. Java runs the world's back offices, but the world's back offices would rather not think about it. For years that meant paying Oracle, the language's commercial steward, whatever Oracle decided Java was worth this quarter. In 2023 Oracle moved to per-employee pricing - you could be billed for Java based on your total headcount, including people who have never written a line of code.

The reaction was predictable. Azul's own 2025 State of Java survey found that 88% of enterprises are considering leaving Oracle Java, citing cost, uncertainty, and audit risk. The catch: Java is load-bearing. You cannot simply turn it off and walk away. You need a runtime that is certified, supported, secure, and identical enough that nothing breaks.

That gap - between wanting out and being able to leave safely - is the whole game.

Three engineers and a refrigerator

In 2002, Scott Sellers, Gil Tene, and Shyam Pillalamarri made a bet that now looks obvious and at the time looked eccentric: that Java performance was a hardware problem. So they built hardware. The early Azul "compute appliances" - the Vega line - were refrigerator-sized boxes that gave Java applications more room to run.

It worked, and then it didn't have to. As commodity servers got fat, the appliance business made less sense. In 2010 Azul did the thing few hardware companies survive: it became a software company. It retired the Vega appliances by 2013 and bet everything on the JVM itself.

The wilder bet was the second one. Azul launched Zulu, a 100% open-source, certified build of OpenJDK - free Java, no lock-in - and figured out how to build a business supporting it. Giving away the product and selling the confidence around it is a strange model. It is also, two decades on, the model the entire market is sprinting toward.

FIG. 1 - The founding team, still in charge. In Silicon Valley, staying at your own company for 20+ years counts as a personality trait.

Two engines and a brain

Azul's product line is easier to understand if you forget the rebrands and watch what each piece does. Old-timers still call them Zulu and Zing.

The Prime story is the one engineers tell at conferences. Java has always had a dirty secret: the garbage collector, the thing that cleans up unused memory, pauses your application while it works. For a website, you never notice. For a stock exchange, a pause is a missed trade. Tene's team built a collector designed to do its work without stopping the application. The boring name is C4. The marketing name is "you stop worrying about pauses."

Receipts, not adjectives

Skeptics are right to ask for numbers. Here are the ones Azul puts its name on. Workday, the HR and finance giant, moved most of its cloud onto Platform Prime. The result it reports is the kind of figure that sounds invented until you see the source.

FIG. 2 - A bar so short it is hard to see. That is rather the point.

It is not one customer. Azul says its runtimes are used by roughly 35% of the Fortune 100 and all ten of the world's top financial trading firms. Named customers span Salesforce, Mastercard, BMW, Priceline, Avaya, Deutsche Telekom, LG, Mizuho, and MEMX, the fast-growing US stock exchange that runs its trading platform on Azul.

FIG. 3 - The receipts. Azul's Intelligence Cloud milestone: 10,000+ customer JVMs pooling optimizations and shaving roughly a fifth off cloud bills.

Keeping Java honest

Strip away the products and Azul's mission is unusually specific: keep a credible, open alternative to proprietary Java alive, and make Java itself faster and cheaper along the way. In a market where one vendor can rewrite the price of a language overnight, that is less a slogan than a public service.

The money agrees. After the Vitruvian and Lead Edge investment in 2020, Thoma Bravo took a majority stake in November 2025, with the earlier backers reinvesting and Azul's founders still at the wheel. Investors do not pile into 20-year-old infrastructure companies for the romance. They do it when revenue has been growing past 50% a year and the tailwind - enterprises fleeing Oracle - shows no sign of dying down.

Why the boring layer wins

The next phase is collective. Intelligence Cloud's pitch is that thousands of JVMs, sharing what they learn about real workloads, can optimize each other - 10,000 of them already collaborating, cloud bills down about 20%. It is a network effect for the least glamorous part of the stack. The runtime that learns from every other runtime is a quietly radical idea.

Which brings us back to that server farm at 2 a.m. The trade still clears in microseconds. The payroll still finishes before dawn. The difference is that today the runtime underneath did it without a single noticeable pause, for noticeably less money, on a Java that no single vendor gets to hold hostage.

Nobody in the building will ever know Azul was there. That has always been the job.

On the record

Interviews, talks, and product walk-throughs from Azul and its founders.

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