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Setting Your Own Default Versions

There are some simple ways to change which application version you use for pre-installed software on this server. Often multiple versions of languages are provided, where such things are relevant.

Java

Java can load it's resources from the both JAVA_HOME and the binaries from the PATH environment variables. This isn't set by default per-user, instead applications will rely on your existing PATH settings to find the relevant Java version and it's necessary component binaries. Updating which version of Java you use is as simple as changing which environment variables you use.

  • To see what versions of Java are available run: java-available-versions
  • To change which version of Java you use you can set the location of JAVA_HOME in your .bashrc file. If I wanted to use Java 17, my process would look like this:
$ java-available-versions
Your Java version: OpenJDK Runtime Environment (build 1.8.0_462-b08)

Looking to change your version?
Choose one of these and set it as JAVA_HOME= inside your .bashrc.
JAVA_HOME Options:
        - /usr/lib/jvm/jre-17
        - /usr/lib/jvm/jre-21
        - /usr/lib/jvm/jre-11

Once you\'ve chosen the version you want, add the following to your .bashrc:

export JAVA_HOME=<selection>
export PATH=${JAVA_HOME}/bin:${PATH}


$ echo 'export JAVA_HOME=/usr/lib/jvm/jre-17' >> .bashrc
$ echo 'export PATH=${JAVA_HOME}/bin:${PATH}' >> .bashrc
$ source .bashrc
$ which java
/usr/lib/jvm/jre-17/bin/java
$ java -version
openjdk version "17.0.16" 2025-07-15 LTS
OpenJDK Runtime Environment (Red_Hat-17.0.16.0.8-1) (build 17.0.16+8-LTS)
OpenJDK 64-Bit Server VM (Red_Hat-17.0.16.0.8-1) (build 17.0.16+8-LTS, mixed mode, sharing)

Python

There are several versions of Python installed. You can see all installed versions using whereis python. You'll likely be choosing between 3.11 and 3.12.

To change the default one that comes up when you type python, you can simply add an alias to your .bashrc like this:

alias python3=/usr/bin/python3.12
alias python=python3

Additional Python Options

There are few "quality of life" factors when working with Python.

  • First, you might find more joy in using a virtual environment when working with software development projects: https://docs.python.org/3/library/venv.html. These can be activated to allow both packages and the version they were created with to be in your PATH.
  • Secondly, for version warriors and more robust projects you might even find tools like uv to be more helpful. https://docs.astral.sh/uv/. This is a powerful tool, with a lot of features, please review at your own risk. The installation instructions work on this server and install only to your user space.