Newbie question about Groovy/Java?

[Tom]

I know this is probably a really stupid question, but I've been digging around for hours, and have been unable to find anything on this. I'm a PHP/Python guy, so I'm not 100% sure how Java works. I am trying to compile an existing open source project written in Groovy. I figured out how to compile it with ant, but I can't seem to run it. I have a directory full of class files. Running them with the "java" command with the groovy jar files in the classpath gives me a "main class not found" error. Without the groovy jar in the classpath, it says it is unable to find the groovy libs or something. If I run the class files with the "groovy" command, it always says I have an unrecognized character.

I know I'm probably missing something huge, but I've been trying for hours and am still unable to figure it out. Yes, there are binaries, but I need to be able to compile this. Also, I'm running GNU/Linux. Thanks a lot