I presume it's the build and go button, but that option isn't highlighted and i cant figure out what to do to get it to work. Is it somethig to do with targets? I've been able to do this function with netbeans before. The build function works and it says build successful and creates a .jar file. Then trying to open the .jar file it says the jar file cannot be launched please check for possible errors. It does compile fine and run in terminal using javac and java commands. I'm using the empty ant based java project in xcode also if that helps. Also which java option would be best suitable to use under xcode? I mean by the different options given when you create a new project.