Getting Enso

Enso packages are best obtained from the releases page of the repository. Each release has an “Assets” section at the bottom. You can click on this to view the list of artifacts from which you can download the most appropriate version.

These assets contain bundles that include the Enso launcher, an engine version, and GraalVM, allowing you to get up and running immediately. Alternatively, you can download just the launcher, which will handle downloading and installing the required components for you.

Nightly Builds

In addition to the official releases, we provide nightly snapshots built on our CI. These can be obtained from the build workflow on GitHub Actions, which should show a list of recent CI builds. The workflow of interest is Engine CI. You can navigate to the most recent build, which will display a list of attached artifacts. The artifact of interest is enso-engine-<version> (currently enso-engine-0.2.1-SNAPSHOT).


The Enso distribution requires to be run with the appropriate version of GraalVM. You can get the Community Edition pre-built distributions from the GitHub releases site. It is important to run Enso with exactly the version specified here. Given that Graal is still a relatively young project, even the minor version changes introduce breaking API changes. The current version of GraalVM required for Enso is 20.2.0, and it must be the Java 11 build.

Before running the Enso packages, make sure that the JAVA_HOME environment variable points to the correct home location of the Graal distribution.

Running Enso

The nightly distribution contains the Enso CLI. It allows to create and run Enso projects from the command line. To launch the Enso CLI, run the bin/enso script (Linux and MacOS) or the bin/enso.bat script (Windows).

Again, it is necessary for you to set the JAVA_HOME variable correctly.


This section lists the most common failures and their probable causes.

  1. The exception java.lang.IllegalArgumentException: Could not find option with name enso-runtime-server.enable. It can contain a different option name. This exception signals problems with the Graal distribution. Make sure you’re running Enso with the correct version of GraalVM. You can verify the version of JDK used by running bin/enso --version. Take note of the version displayed in the Running on section. It should be similar to:

    Running on: OpenJDK 64-Bit Server VM, GraalVM Community, JDK 11.0.8+10-jvmci-20.2-b03
                Linux 4.15.0-112-generic (amd64)

    It could also be caused by not using the launcher scripts and trying to run the component .jar files via java -jar without setting the necessary options. Use the launcher scripts.