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Expanded InstantOn support in Open Liberty

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David Mueller on Jan 30, 2024
Post available in languages: 日本語 ,

The release expands the set of Liberty features that Liberty InstantOn supports. InstantOn now supports features that enable Jakarta and Java XML Web Services and Jakarta and Java Mail functions, and more versions of previously supported features. This release also introduces Java 21 container images and the option to verify the authenticity of the Open Liberty public key.

In Open Liberty

View the list of fixed bugs in

For a list of past security vulnerability fixes, reference the Security vulnerability (CVE) list.

Develop and run your apps by using

If you’re using Maven, include the following code in your pom.xml file:


Or for Gradle, include the following in your build.gradle file:

buildscript {
    repositories {
    dependencies {
        classpath ''
apply plugin: 'liberty'

Or if you’re using container images:


Or take a look at our Downloads page.

If you’re using IntelliJ IDEA, Visual Studio Code or Eclipse IDE, you can also take advantage of our open source Liberty developer tools to enable effective development, testing, debugging, and application management all from within your IDE.

New container images for Java 21

Starting in, you can pull Open Liberty container images that use Java 21 from IBM Container Registry. The images are available in either full or kernel-slim image types and are based on Universal Base Image (UBI) 9 minimal. They include the IBM Semeru Runtimes for Java 21 Java runtime environment (JRE). For more information, see UBI 9 minimal Liberty container images with Semeru Runtime Java 21 support.

InstantOn support for Jakarta XML Web Services, Java Web Services and other features

Open Liberty InstantOn provides fast startup times for MicroProfile and Jakarta EE applications.

InstantOn supports a subset of Open Liberty features. As of the release, the following features are enhanced to support InstantOn, in addition to the set of features included in the initial Liberty InstantOn release:

Feature name Short name Initial InstantOn support

Java Web Services 2.2

jaxws-2.2 and later

Jakarta XML Web Services 3.0

xmlWS-3.0 and later

Jakarta XML Web Services 4.0

xmlWS-4.0 and later

Java Database Connectivity 4.1

jdbc-4.1 and later

Java Database Connectivity 4.3

jdbc-4.3 and later

Application Security 1.0

appSecurity-1.0 and later

Java Mail 1.6

javaMail-1.6 and later

Jakarta Mail 2.0

mail-2.0 and later

Jakarta Mail 2.1

mail-2.1 and later

Password Utilities 1.0

passwordUtilities-1.0 and later

Admin Local Connector 1.0

localConnector-1.0 and later

This enhancement enables you to rapidly deploy applications that use these features by using Open Liberty InstantOn. For more information, see Faster startup for containerized applications with Open Liberty InstantOn.

Verify the authenticity of the Open Liberty public key

The Open Liberty project uses its private key to digitally sign each Open Liberty release. You can use the Open Liberty public key to check the signature, verify that the package was released by Open Liberty, and that it was not modified since its release. Starting in version, you can also verify the authenticity of the Liberty public key by using a provided certificate (.cer) file. For more information, see Verifying Open Liberty release package signatures.

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