deploy profile
In addition to main POM, for open source projects pl.wrzasq.parent:parent-opensource defines deploy profile (to use
as mvn -P deploy), which performs deployment to public repositories.
Plugins
org.apache.maven.plugins:maven-gpg-plugin
Bound to phase verify, creates a certificate, which is needed to publish project artifact to staging repository.
org.sonatype.plugins:nexus-staging-maven-plugin
Open source projects are configured to be deployed into central OSS Sonatype repository.