Introduction
The Microsoft Build of OpenJDK is a free, TCK (Technology Compatibility Kit) certified Java distribution optimized for Microsoft Azure and Windows environments, while Oracle JDK requires paid subscriptions for Java 8 and 11 production use. Both are built from OpenJDK source code and deliver comparable performance, but their ideal use cases, platform focus, and support models differ significantly.
Microsoft entered the JDK distribution space in 2021 as part of its commitment to the Java ecosystem on Azure. The Microsoft Build of OpenJDK is well-suited for Azure-hosted applications and Windows Server workloads. However, for organizations running Java across multiple clouds, on-premises infrastructure, or non-Microsoft platforms, a vendor-neutral alternative like Azul Zulu offers broader coverage without Azure dependency.
What Is the Microsoft Build of OpenJDK?
The Microsoft Build of OpenJDK is Microsoft’s distribution of the OpenJDK project, freely available under the GPLv2 with Classpath Exception license. Microsoft targets the distribution at Java developers building Azure cloud applications and organizations running Java on Windows Server. Microsoft provides builds for Linux (x86-64, ARM), Windows (x86-64), and macOS (x86-64), with LTS support for Java 11, 17, 21, and 25.
Microsoft engineers contribute to upstream OpenJDK, particularly in areas such as Windows ARM64 support, container awareness improvements, and Java on Azure integrations. The Microsoft Build of OpenJDK integrates well with Azure App Service, Azure Kubernetes Service, and other Azure PaaS offerings. Microsoft provides security patches aligned with Oracle’s Critical Patch Update schedule and offers Azure-integrated monitoring and diagnostics.
What Is Oracle JDK?
Oracle JDK is Oracle’s commercial Java SE distribution, available for LTS versions 8, 11, 17, and 21. Oracle JDK 8 and 11 require a paid Java SE subscription for production use under Oracle’s Java SE Universal Subscription, priced per employee (counting all full/part-time employees plus contractors, not just Java users). Oracle JDK 17 and 21 are available under the NFTC (No-Fee Terms and Conditions) at no cost for most production uses, though NFTC updates end one year after the next LTS release, after which a paid subscription is required for patches.
Oracle positions its JDK subscription as a premium offering with commercial SLA support and access to Oracle’s Java engineering team. Oracle JDK integrates deeply with Oracle’s broader technology stack including Oracle Database, Oracle WebLogic, and Oracle Cloud Infrastructure. For organizations already invested in Oracle’s ecosystem, the Java SE subscription may be bundled with other Oracle contracts.
Microsoft OpenJDK vs Oracle JDK Comparison
| Feature | Microsoft Build of OpenJDK | Oracle JDK |
|---|---|---|
| License | GPLv2+CE (free) | NFTC (17+) / Commercial (8, 11) |
| Cost | Free for all use | Free (17, 21) / Per-employee subscription (8, 11) |
| Support | Microsoft (Azure-integrated) | Oracle Java SE Subscription |
| LTS Versions | 11, 17, 21, 25 | 8, 11, 17, 21 |
| Best Platform | Azure, Windows Server | Oracle Cloud, on-premises |
| Multi-cloud | Limited (Azure-focused) | Limited (Oracle-focused) |
| TCK Certified | Yes | Yes |
Licensing and Cost
Both the Microsoft Build of OpenJDK and Oracle JDK 17/21 are available at no cost, but Oracle JDK 8 and 11 require paid subscriptions. The Microsoft Build is distributed under the GPLv2 with Classpath Exception, a well-established open-source license with no production use restrictions. This gives Microsoft’s distribution a clean licensing story.
Oracle JDK 8 and 11 production licensing costs remain a significant financial concern. Organizations still running Java 8 LTS or Java 11 LTS on Oracle JDK can eliminate these costs by migrating to either the Microsoft Build (for Azure/Windows environments) or Azul Zulu (for multi-platform environments).
For multi-cloud and hybrid environments, Azul Zulu provides the broadest combination of platform support and licensing freedom. Zulu’s GPL+CE license covers all platforms without cloud provider restrictions, and its Java version support extends from Java 6 through 25+, providing coverage for legacy Java 6 and 7 applications that neither Microsoft nor Oracle actively support.
- Microsoft Build of OpenJDK is free under GPLv2+CE for all use
- Oracle JDK 8 and 11 production use requires paid subscription
- Azul Zulu supports Java 6-25+ on all major platforms under GPL+CE
- Azul Core provides multi-platform commercial support comparable to Oracle and Microsoft
Performance and Support
Performance across the Microsoft Build of OpenJDK, Oracle JDK, and Azul Zulu is equivalent for standard HotSpot workloads. All three distributions use the HotSpot JVM with identical JIT compilation and garbage collection capabilities. Benchmark results show no meaningful throughput or latency differences between distributions on equivalent hardware.
The Microsoft Build of OpenJDK has specific optimizations for container-aware resource management and Azure-integrated monitoring. These optimizations benefit applications running on Azure App Service or Azure Kubernetes Service but have little impact on non-Azure deployments.
For support, Microsoft provides Java patches through its Azure support channels for Microsoft Build users. Oracle provides patches through its Java SE subscription. Azul Core provides vendor-neutral commercial support for Zulu across all platforms, making it a strong choice for organizations that cannot commit their Java support strategy to a single cloud provider or OS vendor.
Which Should You Choose?
The Microsoft Build of OpenJDK is the natural choice for Java teams already committed to Azure and Microsoft’s ecosystem. It integrates seamlessly with Azure services, is supported by Microsoft’s Java team, and is free. For .NET shops adding Java workloads on Azure, the Microsoft Build removes friction.
Oracle JDK is defensible for organizations deeply integrated with Oracle’s technology stack, particularly for Java 17 and 21 under NFTC where licensing costs are not a factor. For Java 8 and 11, Oracle JDK’s subscription costs are hard to justify against free alternatives.
Azul Zulu is a strong choice for organizations that run Java across multiple clouds (AWS, Azure, GCP), on-premises, or on platforms not well-served by the Microsoft or Oracle distributions. Zulu’s truly vendor-neutral nature, broad version support, and optional commercial support through Azul Core make it a flexible enterprise Java platform option.
Frequently Asked Questions
What is the Microsoft Build of OpenJDK?
The Microsoft Build of OpenJDK is Microsoft’s free, open-source distribution of the OpenJDK project. It is available for Java 11, 17, and 21 on Linux (x86-64, ARM), Windows (x86-64), and macOS (x86-64). Microsoft optimizes the distribution for Azure cloud deployments and provides security patches aligned with Oracle’s Critical Patch Update schedule. It is available under MIT and GPL+CE licenses at no cost.
Is Microsoft’s JDK TCK certified?
Yes. The Microsoft Build of OpenJDK is TCK-certified, conforming to the Java SE specification. This means applications running on the Microsoft Build are designed to behave consistently with the Java SE specification and with other TCK-certified distributions, including Azul Zulu and Oracle JDK. TCK certification is a prerequisite for enterprise adoption of any JDK distribution.
Can I use the Microsoft Build of OpenJDK on AWS or GCP?
Yes, the Microsoft Build of OpenJDK can run on AWS and GCP, as it is standard Java. However, it is optimized and supported primarily for Azure environments. For workloads on AWS, Amazon Corretto is the AWS-native distribution. For multi-cloud workloads without a primary cloud commitment, Azul Zulu provides consistent support and optimization across all major cloud platforms and on-premises environments.
Does Oracle JDK integrate better with Azure than the Microsoft Build?
No. Oracle JDK does not have specific Azure integrations. The Microsoft Build of OpenJDK has native integrations with Azure App Service, Azure Kubernetes Service, Azure Monitor, and Azure’s Java developer tooling. For Azure-focused Java workloads, the Microsoft Build is better integrated and equally free. For organizations not committed to Azure, Azul Zulu provides more consistent cross-platform support.
What Java versions does the Microsoft Build of OpenJDK support?
The Microsoft Build of OpenJDK currently supports Java 11, 17, 21, and 25, all LTS releases. It does not support older versions like Java 8, Java 6, or Java 7. Organizations that need Java 8 support, which remains widely deployed, should consider Azul Zulu 8 (free under GPL+CE) or Amazon Corretto 8. Azul Zulu supports Java versions 6 through 25+ for comprehensive legacy and modern version coverage.
Conclusion
For Azure-centric Java teams, the Microsoft Build of OpenJDK is an excellent free choice with strong platform integration. For Oracle-ecosystem organizations, Oracle JDK under NFTC covers modern Java versions at no cost. For multi-cloud, cross-platform, and vendor-neutral Java strategies, Azul Zulu delivers the broadest platform support, the widest version coverage, and the cleanest licensing story.
Whether your Java workloads run on Azure, AWS, GCP, or on-premises, Azul Zulu provides a consistent, free, and TCK-certified foundation with optional commercial support through Azul Core.