Merge pull request #2633 from quarkusio/dmlloyd-patch-1

Update references from OpenJDK to HotSpot in post

Author: geoand

_posts/2026-05-04-semeru-scc.adoc

@@ -3,15 +3,15 @@ layout: post
 title: 'Faster Startup on IBM Semeru with OpenJ9 Shared Classes Cache'
 date: 2026-05-06
 tags: performance aot semeru
-synopsis: 'Quarkus 3.35 brings great startup improvements to IBM Semeru Runtimes. The same `quarkus.package.jar.aot.enabled=true` flag that activates Project Leyden on OpenJDK now automatically generates an OpenJ9 Shared Classes Cache - no code changes needed.'
+synopsis: 'Quarkus 3.35 brings great startup improvements to IBM Semeru Runtimes. The same `quarkus.package.jar.aot.enabled=true` flag that activates Project Leyden on HotSpot-based JVMs now automatically generates an OpenJ9 Shared Classes Cache - no code changes needed.'
 author: geoand
 ---
 
-Slow startup times have long been a challenge for Java applications. Project Leyden addressed this for OpenJDK 25+, but what about IBM Semeru users?
+Slow startup times have long been a challenge for Java applications. Project Leyden addressed this for JVMs like Temurin 25+, which are based on HotSpot, but what about users of JVMs based on IBM OpenJ9 like Semeru?
 
 In our https://quarkus.io/blog/leyden-2/[previous post], we described how we integrated Project Leyden into Quarkus, bringing JVM startup way down.
 
-But not everyone runs OpenJDK.
+But not everyone runs HotSpot-based JVMs.
 
 Many teams, especially in enterprise environments, run https://www.ibm.com/semeru-runtimes[IBM Semeru Runtimes], IBM's production Java runtime built on the https://eclipse.dev/openj9/[Eclipse OpenJ9] JVM.
 These teams deserve the similar startup improvements, with the same ease of use.
@@ -131,11 +131,11 @@ When `quarkus.package.jar.aot.enabled=true` is set and no explicit type is confi
 | Shared Classes Cache (`-Xshareclasses`)
 | `app-scc/` directory
 
-| OpenJDK 25+
+| HotSpot (25+)
 | Leyden AOT (`-XX:AOTCache`)
 | `app.aot` file
 
-| Older OpenJDK
+| Older HotSpot
 | AppCDS (`-XX:SharedArchiveFile`)
 | `app-cds.jsa` file
 |===
@@ -155,7 +155,7 @@ Valid values are `AUTO` (the default), `AOT`, `AppCDS`, and `SCC`.
 
 This is the design decision we are most proud of in this work. Your build configuration, CI pipeline, and Dockerfile don't need to know which JVM will run the application. Set `quarkus.package.jar.aot.enabled=true`, and the build adapts.
 
-This matters in practice. Teams that standardize on Semeru for some services and OpenJDK for others can use the same Quarkus build configuration everywhere. Switching JVMs doesn't require touching `application.properties`.
+This matters in practice. Teams that standardize on Semeru for some services and HotSpot for others can use the same Quarkus build configuration everywhere. Switching JVMs doesn't require touching `application.properties`.
 
 It also means that the Quarkus documentation, guides, and examples work the same way regardless of the JVM.
 When we write "enable AOT for faster startup," that statement is true whether you run HotSpot, Semeru, or an older JDK.
@@ -185,7 +185,7 @@ While the user experience is intentionally identical, there are a few technical
 | Single step: cache is populated during the training run itself
 
 | *JVM requirement*
-| OpenJDK 25+
+| Version >=25
 | Any IBM Semeru version
 
 | *Maturity*
@@ -286,7 +286,7 @@ We would like to thank the OpenJDK team at IBM for their collaboration. The disc
 
 == Conclusion
 
-The beauty of this integration is its simplicity: one flag, multiple JVMs, optimal performance everywhere. Whether you're running OpenJDK or IBM Semeru, Quarkus has you covered, as Quarkus has always been about meeting developers where they are.
+The beauty of this integration is its simplicity: one flag, multiple JVMs, optimal performance everywhere. Whether you're running HotSpot or Semeru, Quarkus has you covered, as Quarkus has always been about meeting developers where they are.
 
 We will continue tracking developments in both Project Leyden and OpenJ9 to bring you the best performance on whatever platform you choose.