These are old instructions for setting up a Groovy-Eclipse development environment manually. It is much easier to use the new automated setup based method instead.
Groovy-Eclipse is intended to be developed using Eclipse. Download and install the "Eclipse IDE for Eclipse Committers" package for your operating system.
On the Eclipse menu bar, select Help -> Install New Software.... In the Install window, paste the Groovy-Eclipse update site https://groovy.jfrog.io/artifactory/plugins-release/e4.35 into the Work with: field and press enter. Check the box next to "Main Package", then click the Next button a couple of times, accept the license agreement, and let Eclipse restart.
If you installed extra Groovy compiler versions, then you must activate Groovy 3.0 compiler for Groovy-Eclipse. On the Eclipse menu bar, select Window -> Preferences. In the Preferences window, go to Groovy -> Compiler. Click the Switch to 3.0.24 button, and let Eclipse restart.
On the Eclipse menu bar, select Help -> Install New Software.... In the Install window, select 2025-03 - https://download.eclipse.org/releases/2025-03 from the Work with: field and enter "exeuction" in the filter. Check the boxes next to "API Tools Execution Environment Descriptions", and click the Next button a couple of times, accept the license agreement, and let Eclipse restart.
On the Eclipse menu bar, select Window -> Preferences. In the Preferences window, go to Java -> Installed JREs and add JDK 8, 11 and 17. Then go to Java -> Installed JREs -> Execution Environments, select JavaSE-1.8, and check the box next to JDK 8 in the list of compatible JREs. Repeat for JDK 11, 17 and 21.
On the Eclipse menu bar, select Window -> Preferences. In the Preferences window, go to Plug-in Development -> API Baselines. Select either Ignore or Warning instead of Error in the Missing API Baseline: drop-down list.
The source code can be obtained by cloning the repository:
https://github.com/groovy/groovy-eclipse.git
Import the projects that you want to work with into your workspace. If you do not know how to clone a repository or import projects from a repository, refer to the EGit User Guide.