It is possible to compile Groovy++ sources with Maven using http://groovypp.artifactoryonline.com/groovypp/libs-releases-local/ repository and something like

<dependency>
    <groupid>org.mbte.groovypp</groupid>
    <artifactid>groovypp-all</artifactid>
    <version>0.4.225_1.7.10</version>
</dependency>

or for example

<dependency>
    <groupid>org.mbte.groovypp</groupid>
    <artifactid>groovypp</artifactid>
    <version>0.4.225_1.8.0-rc-4</version>
</dependency>

There are four types of artifacts

• groovypp
• groovypp-all - to be used with groovy-all.jar
• groovypp-nodep - the one without maven dependencies
• groovypp-all-nodep

The version number consists from two parts

• version of Groovy++ itself
• version of regular Groovy it compiled against

Please note that you need to replace version number above to the latest available version and 1.7.x or 1.8.x variant depending on your use

See this post and its update for more details. Full examples are available here and here.