In the early 1990s, the software industry had a massive problem: developers had to rewrite and recompile their software for every different processor and operating system.
In 1995, a team of engineers at Sun Microsystems led by James Gosling unveiled Java with a bold promise:
“Write Once, Run Anywhere” (WORA)
Today, more than three decades later, Java is one of the most widely used programming languages on Earth, running on billions of devices, powering the backend of global banking systems, and driving high-throughput cloud infrastructure.
In this lesson, we will explore the history of Java, the Oracle commercial transition, and why the OpenJDK open-source revolution makes Java free, open, and vibrant today.
1. The Origins: Sun Microsystems & The Green Team (1991–1995)
In 1991, James Gosling, Mike Sheridan, and Patrick Naughton formed the “Green Team” at Sun Microsystems. Initially designed for interactive television set-top boxes (originally named Oak after a tree outside Gosling’s office), the team quickly realized the technology was perfect for the emerging World Wide Web.
In May 1995, Java 1.0 was officially announced. It revolutionized development through three core innovations:
- The Virtual Machine (JVM): Programs compile to portable intermediate bytecode instead of hardware-specific binary.
- Automatic Memory Management: Automatic Garbage Collection freed developers from manual memory deallocation bugs (like dangling pointers in C++).
- Robust Object-Oriented Design: Clean, type-safe syntax that prevented common memory corruption vulnerabilities.
2. The Oracle Acquisition & The Licensing Shift (2010–2019)
In 2010, Oracle Corporation acquired Sun Microsystems for $7.4 billion, gaining ownership of Java, the JVM, and the official Trademark.
In 2018–2019, Oracle changed its licensing model for the commercial Oracle JDK, requiring paid enterprise subscriptions for production updates. This caused confusion and anxiety across the global software industry: Is Java still free?
The answer was a resounding YES, thanks to OpenJDK.
3. The OpenJDK Open-Source Ecosystem
OpenJDK (Open Java Development Kit) is the official, open-source reference implementation of the Java SE Platform, released under the GNU General Public License (GPLv2 with Classpath Exception).
When Oracle transitioned its commercial distribution, major technology companies joined forces to sponsor, build, test, and distribute completely free, enterprise-grade production builds of OpenJDK:
Major Trusted OpenJDK Distributions Today:
- Eclipse Temurin (Adoptium): Governed by the Eclipse Foundation and backed by IBM, Red Hat, Microsoft, and Google. The gold standard open-source distribution.
- Microsoft Build of OpenJDK: Used internally to power Microsoft Azure, LinkedIn, and Minecraft.
- Amazon Corretto: A multiplatform, production-ready distribution with Long-Term Support (LTS) from Amazon Web Services.
- Azul Zulu: Highly optimized enterprise builds with extensive architecture support.
[!IMPORTANT] All official OpenJDK distributions pass the rigorous TCK (Technology Compatibility Kit) test suite, ensuring 100% specification compatibility. A Java program written for Temurin runs identically on Amazon Corretto or Microsoft OpenJDK.
4. Modern Java Release Cadence
In the past, Java releases took 3 to 5 years between major versions (e.g. Java 6 to Java 7 to Java 8).
Today, the Java ecosystem operates on a modern, predictable 6-month release cadence:
- Every 6 months (March and September): A new feature release (e.g. Java 21, 22, 23, 24, 25, 26).
- Every 2 years: A Long-Term Support (LTS) release designed for enterprise stability (Java 17, Java 21, Java 25).
Summary Checklist
- Java was created in 1995 by Sun Microsystems to enable cross-platform portability.
- The Java Virtual Machine (JVM) enables “Write Once, Run Anywhere”.
- OpenJDK is the 100% free, open-source foundation of modern Java.
- Trusted enterprise distributions like Eclipse Temurin and Microsoft OpenJDK provide free Long-Term Support.
Next Step in the Curriculum
Now that you know the rich history of Java and its open-source ecosystem, let’s explore: Why do the world’s largest companies still choose Java, and how does Object-Oriented Programming (OOP) work?