mvn -Djetty.port=9090 jetty:run

<plugin>
    <groupId>org.mortbay.jetty</groupId>
    <artifactId>maven-jetty-plugin</artifactId>
    <version>6.1.16</version>
    <configuration>
        <systemProperties>
            <systemProperty>
                <name>tapestry.execution-mode</name>
                <value>development</value>
            </systemProperty>
            <systemProperty>
                <name>jetty.port</name>
                <value>9090</value>
            </systemProperty>
        </systemProperties>
    </configuration>
</plugin>