How do I write a plugin?
Writing a plugin requires a working knowledge of Java and some familiarity with jEdit’s Plugin API. There is a tutorial on plugin development in the jEdit User’s Guide. The source code distribution for jEdit also includes the source for an example plugin, Quick Notepad, which is discussed in the tutorial. To learn more about plugin development, take a look at the source code for other plugins, particularly those whose features or user interface you might use as a model. The jedit-devel mailing list and the message boards at jEdit Community are also available for specific questions.