jpct jar is only a library. It doesn't have a main class to get the program up and running. If you go into the example files, there will be a file that says something like run.bat, can't remember for sure. The batch file combines jpct with the example code and gets it running. It's really a small txt file that you can open with notepad and look at, but it's also an executable that you can double click on. By the way, for me, I find netbeans IDE a big help for setting up a project and including libraries. It may be different for other people, but all the classpath hocus pocus drives me nuts with java.