I set my java runtime options in Eclipse's Window > Prefs > Java > Installed JREs > Default VM Arguments. Since this setting is sufficient for all my main() entry points, I do not bother with customizing the "run configurations". It looks like nice flexibility but I probably will never need it. I was worried that I would have to repeat my VM arguments in the run configurations and so I started to copy my VM arguments but after an experiment it seems that I do not have to. Now I will have the opposite worry that I have some unintended customizations.
To eliminate the second worry, is there a way to eliminate the clutter visible in the Run drop down menu? What about the "Launch configurations" visible in the JAR export dialog? Is a run configuration the same thing as a launch configuration? How do I eliminate the multiple launch configurations?
I am on Eclipse Indigo on Ubuntu.
Edit After I manually delete all the run configurations, and proceed to do an export, buttons are greyed-out so I can't proceed. When I select the launch configuration drop-down, I end up with only one choice, from an unrelated project. I then created a run configuration for the real main entry point for the current project. I expect the clutter will return as I continue to use Eclipse.
Best Answer
One simple way would be to organize your projects by Eclipse workspace, which would limit the "run configurations" list only to the project referenced in a given workspace.
Switching workspaces would reset that list to the ones recorded for the projects of the new workspace.
Note: the OP's answer regarding launches file location isn't the only location possible.
The official one is:
But you can copy them enywhere else you want (as explained in "How do I save Eclipse launch profiles across workspaces?"), either by manually copying those files or by sharing them:
See "Which eclipse files belong under Version Control".
Once you know where they are saved, a simple delete is enough to make them disappear from the launcher menu.