Eclipse .gitignore template

.project and .classpath are the two files that define an Eclipse project: what it is called, which builders run on it, and where its sources and dependencies are. Whether ignoring them is right depends entirely on whether something else can regenerate them. A project built by Maven or Gradle can, because the build tool has an import step. A project with no build tool at all cannot, and ignoring these files means a clone has no project to open.

.settings is the per project preferences directory, holding compiler compliance level, formatter settings and per project overrides of workspace preferences. This is the folder with the strongest argument for being tracked, since a shared formatter setting prevents whitespace churn, and it is worth negating a specific file inside it if your team relies on one.

.metadata is the workspace metadata directory. It is not part of a project at all: it belongs to the workspace that contains projects, and it holds indexes, logs and plugin state. It only appears in a repository when someone has created the workspace inside the project folder, which is a mistake in itself.

bin is the default output directory for a project compiled by the editor rather than by a build tool. tmp and *.tmp are working files. local.properties holds machine specific paths, which is the same convention Android tooling uses and the same reason applies: it names directories that exist only on one machine.

The remaining rules cover editor debris: *.bak, *.swp and *~.nib are backup and swap files, *.launch is a saved run configuration, and .loadpath, .recommenders, .externalToolBuilders and *.pydevproject come from specific plugins. A saved run configuration is occasionally worth sharing, so if your team relies on one, add a negation for that specific file rather than dropping the whole rule.