Hey if you trust me and do not care about the source code go right ahead and click the file named: RoRender.jar and then on the following page hit download and you can run the program, assuming you have java installed.
If however you care about security & sourcecode I included it in the file also named RoRender, you are looking for the .java file. Also if you you use an extractor, like win-rar or Dr.-Unarchiver, then you can see the java source code inside the .jar file.