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IBM Semeru Runtime Open Edition vs Microsoft Build of OpenJDK: catalog facts
IBM Semeru Runtime Open Edition	Microsoft Build of OpenJDK
Best for: Java developers wanting an OpenJ9-based OpenJDK build	Best for: Java developers who want a free, long-term supported JDK
Free Free to download, with optional paid enterprise support from IBM.	Free Free of charge and open source.
macOS, Command line	Windows, macOS, Linux, Command line
Uses the Eclipse OpenJ9 JVM instead of HotSpot Drop-in replacement for other OpenJDK builds All 3 strengths for IBM Semeru Runtime Open Edition Uses the Eclipse OpenJ9 JVM instead of HotSpot Drop-in replacement for other OpenJDK builds Free binaries with optional commercial support	Long-term supported releases at no cost Builds for macOS, Linux and Windows All 3 strengths for Microsoft Build of OpenJDK Long-term supported releases at no cost Builds for macOS, Linux and Windows Patches are upstreamed to OpenJDK by default
Only useful to people running or developing Java software OpenJ9 tuning options differ from HotSpot	One of many OpenJDK distributions with similar contents Support focus leans towards Microsoft's own ecosystem
Downloadable app	Downloadable app
Open source	Open source
License not stated	License not stated
No account needed	No account needed
Offline features available	Offline features available
Official website Full listing and sources Sources for IBM Semeru Runtime Open Edition developer.ibm.com/languages/semeru-runtimes Catalog checked October 1, 2026	Official website Full listing and sources Sources for Microsoft Build of OpenJDK microsoft.com/openjdk Catalog checked October 1, 2026

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