Instructions on downloading and installing Repast Simphony on various platforms can be found in the Quick Start Guide. Repast Simphony is a Java application and requires at least Java 8 to be installed. We currently recommend Java 11. If you do not have Java installed, the following options are suggested:
  • Windows users may choose to install the Java 11 Development Kit (JDK) included with the Repast Simphony Windows installer. This will install Java as a folder within the Repast installation location and will not interfere with existing Java or Repast installations.
  • macOS, linux, and Windows users may download a Java 11 JDK from Adoptium (formerly AdoptOpenJDK). Select Temurin 11 (LTS).
    • macOS users should double click on the downloaded file to install the package.
    • Windows users should unzip the downloaded file and copy the folder to any convenient location. The OpenJDK installers no longer set the system PATH or JAVA_HOME, so this needs to be done manually. This post on Stack Overflow desribes how to configure OpenJDK for Windows.
    • Linux users should try the system package manager to download and install an appropriate JDK. Alternatively, the OpenJDK 11 tarball can be extracted an manually installed on linux. For example, the Instructions for installing OpenJDK on Ubuntu 1804.

Why OpenJDK / Adoptium?

In the past users have typically downloaded a Java Development Kit (JDK) distribution from Oracle and used it for free. These releases were built with the OpenJDK source with some non-essential proprietary extras added. However, with the release of Java 11, Oracle's JDK is no longer free for commercial use. For this reason, we are recommending users install an Adoptium (formerly AdoptOpenJDK) release built from OpenJDK source. Java 11 has been designated a long term support (LTS) release and as such will continue to be supported by the OpenJDK team with bug and security fixes for 4 years. The Adoptium project provides JDK binaries for all of the major platforms built from the OpenJDK source using a robust build and test system.

See here for additional information on Oracle and OpenJDK.