All these are available in the JVM world via Rhino but it is kind of slow...
Maybe it will get better with Nashorn with Java 8 but it will take some time.
Additionally we make use of livereload-jvm at the server side that can notify browser plugins which will reload the page. I'm pretty sure it will work flawlessly on Mac too.
People say that support for Windows has become pretty good these days so it should work there too. Since recently Wicket itself uses the solution described above to execute its Java Script unit tests. However, sometimes Apache Wicket code become damn verbose.
From time to time Wicket users ask questions related to how to deal with background jobs in Wicket. "How do I make Application or Session available to a background thread?
In my daily job we switched from based build to Less4j because it is much faster and we have a lot of Less resources! But with some little, yet powerful Groovy DSL written, we can extend Wicket to simplify common tasks, and to delete over 30-40% of verbose code.
A couple of days ago the Wicket in Action website was unavailable without any notice.
This makes the HTML file really easy to understand.
This file makes applications robust and boosts its performance.