Where to ask

GitHub issues, on the repository concerned. That is where the maintainers are. There is no Plexus mailing list — if you find one referenced in older documentation on this site, it is defunct.

Each project on the overview page links to its own repository. If you aren't sure which one owns the behaviour you're seeing, open the issue wherever seems closest and we'll move it.

Building

mvn verify. No profile or local setup is required. CI builds across JDK 8, 21 and 25 on Linux, Windows and macOS.

Code style

Formatting is enforced by the build, via Spotless and palantir-java-format. Don't hand-format, and don't reformat code you aren't otherwise touching. Before pushing:

mvn spotless:apply

If CI fails on spotless:check, running that command and committing the result is the whole fix.

This page previously offered maven-eclipse-codestyle.xml and maven-idea-codestyle.xml for import into your IDE. Those predate Spotless and no longer match what the build enforces, so they are no longer linked from here. The files themselves are still served, so any existing link to them keeps working.

Licence headers

New files take the standard header used by the files around them — Apache-2.0 for everything except Modello, which is MIT. Please do not update or normalise existing copyright headers, including the older Codehaus Foundation ones; they record who contributed what.

Pull requests

One concern per pull request, a test where the change is testable, and an explanation of why in the description. These libraries are consumed transitively across most of the Maven plugin ecosystem, so changes to public API need discussion in an issue first — deprecate rather than remove.

Security

Please do not open a public issue for a vulnerability. See SECURITY.md.