If you are interested in Groovy, you can also use this language and a combination of other tools to create your own plugins—you don't have to stick to Java and Maven if you don't want to.
This page explains how to modify your project to use a build.gradle file in place of the Maven POM file that we used previously:
http://jenkins-ci.org/content/gradle-fy-your-jenkins-plugin-project
You can then execute commands such as gradle jpi, gradle check, gradle install, and so on to build and manage the plugin life cycle without Maven.
This CloudBees presentation illustrates the use of Groovy instead of Java for the plugin itself:
https://www.cloudbees.com/event/topic/groovy-way-write-jenkins-plugin
This is an increasingly popular approach due to the power and simplicity of Groovy. It also explains how you can replace Jelly with Groovy—using the same language (Gradle is based on Groovy, so… it's all Groovy!) throughout the development process makes a lot of sense.