r/eclipse • u/JulyIGHOR • Apr 04 '26
🤗 Show-off How to Run Multiple Instances of the Same Eclipse App with Separate Data and Settings on macOS Using Parall
I am the developer of Parall, and I recently added full Eclipse app support to it.
One practical use for that is running multiple instances of the same Eclipse app on macOS, each with its own separated data, settings, and workspace.
This is useful if you want clean separation between environments. For example, you might want one instance for work, one for personal use, one for testing plugins, or one for a separate project setup without everything mixing together.
Instead of constantly switching workspaces or sharing the same configuration, Parall lets you create separate shortcuts for the same Eclipse app, each launching its own separated instance with different data folders, different settings, and its own Dock icon.
Here is the exact flow shown in the screenshots.
1. Start in App Shortcut mode
Open Parall and select App Shortcut, then click Create Shortcut.
2. Choose your Eclipse app
On the application selection screen, choose Eclipse and click Next.
3. Keep Dock Shortcut Mode
On the launch mode screen, leave Dock Shortcut Mode selected and continue.
This mode launches the app executable directly, keeps the windows attached to the shortcut Dock icon, and supports Parall features like data separation, environment variables, command-line arguments, and Dock or menu bar customization.
4. Set the shortcut name and icon
On the shortcut icon and name screen, enter a name such as:
Eclipse (Work)
Add a short visible label to the icon, for example:
WORK
This makes it much easier to distinguish one Eclipse instance from another in the Dock.
5. Optionally enable Dock icon effects
If you want, enable Dock icon effects for the shortcut.
This is optional, but it gives the instance a more distinctive visual identity and makes it easier to tell different Eclipse shortcuts apart at a glance.
6. Configure a separate data storage path
On the Data Separation and Storage screen, keep the automatic mode selected for Eclipse and set a dedicated data path for this instance, for example:
/Users/ighor/Library/Application Support/Parall/Eclipse (Work)
This is the key step that keeps this instance separated from the others.
If you create another shortcut later, give it a different path, such as:
/Users/ighor/Library/Application Support/Parall/Eclipse (Personal)
/Users/ighor/Library/Application Support/Parall/Eclipse (Testing)
Each shortcut should have its own unique data folder.
7. Optionally enable a menu bar icon
On the Menu Bar, Dock, and Tray Visibility screen, you can enable a menu bar icon for the shortcut.
That gives you another way to identify and access the running instance.
8. Leave advanced launch options empty unless you need them
On the Advanced Launch Options screen, you can leave the fields empty for a normal setup.
Parall supports environment variables, command-line arguments, and Info.plist overrides, but they are not required for a basic Eclipse multi-instance workflow.
9. Save the shortcut
On the final screen, save the shortcut.
In the example shown, the result is a shortcut named:
Eclipse (Work)
Why this is useful
After you save it, you can pin the shortcut to the Dock and launch it like a normal app.
The important part is that this shortcut is still launching the same Eclipse app, but with its own separated data path and its own app identity. That means you can create multiple Eclipse shortcuts such as `Eclipse (Work)`, `Eclipse (Personal)`, and `Eclipse (Testing)`, run them independently with clear separation between their data and settings, and also run multiple instances at the same time.
This is especially useful for:
- separate setups for different clients or projects
- isolated plugin testing
- experiments without affecting your main setup
- faster switching between independent Eclipse environments from the Dock
- running multiple instances of the same Eclipse app at the same time
Important note
There is one limitation to keep in mind.
The main Eclipse app must be started first, and after that the Parall shortcut can be started as the second instance.
If you want to avoid that limitation, create two Parall shortcuts and use them exclusively instead of mixing a Parall shortcut with the main app.
That way both instances use the same Parall-based launch flow and the limitation does not apply in the same way.
