maven-archetype-plugin is an archetype which contains a sample Maven plugin:
project |-- pom.xml `-- src `-- main `-- java `-- MyMojo.java
To create a new project from this archetype, type:
mvn archetype:generate -DarchetypeGroupId=org.apache.maven.archetypes -DarchetypeArtifactId=maven-archetype-plugin -DarchetypeVersion=5-SNAPSHOT