Download the latest binaries from GraphWalker:

Last stable build can be found here
http://graphwalker.org:8080/job/graphwalker/lastStableBuild/org.graphwalker$graphwalker/

The source code can be found here:
https://github.com/KristianKarl/GraphWalker 

The JavaDoc is here:
http://graphwalker.org:8080/job/graphwalker/javadoc

More info about the project:
http://graphwalker.org:8080/job/graphwalker/site

Get the code:
Fork a repo

Then build it as a maven project:
mvn package

To skip the unit tests, and build the standalone jar file:
mvn -Dmaven.test.skip=true assembly:assembly

To add GraphWalker as a dependency to your maven project, add to your pom.xml file:

<dependency>
    <groupId>org.graphwalker</groupId>
    <artifactId>graphwalker</artifactId>
    <version>2.5.15</version>
</dependency>