setx JAVA_HOME "C:\Java\jdk-23" /M
setx PATH "%JAVA_HOME%\bin;%PATH%" /M

The new JDK automatically creates a class data sharing archive, reducing startup time by 30–40%.

After installing the new JDK, you must set JAVA_HOME and update PATH. On Windows:

setx JAVA_HOME "C:\Program Files\Java\jdk-21"
setx PATH "%PATH%;%JAVA_HOME%\bin"

On Linux/macOS:

export JAVA_HOME=/usr/lib/jvm/jdk-21
export PATH=$JAVA_HOME/bin:$PATH

The download page reflects the diverse environments where Java now operates.

The "New" section of the Oracle technologies page highlights features that fundamentally change how Java code is written and executed.

I can summarize the 2019–2023 license shifts, Oracle No-Fee Terms, and what’s free for development/production.

Perhaps the most transformative feature in modern Java is Virtual Threads. Historically, Java threads mapped 1:1 to operating system threads, limiting scalability.