There are many ways for you to help Jakarta MVC
The specification mailing lists are open for everyone.
Feel free to create issues if have feedback or run into problems
If you spent some time on the spec and learned about how Jakarta MVC works, why not write a blog post about it? This will help others to get started. See the Learn section for a list of blog posts and create a pull request for that page to add your own post to the list.
You would like to contribute code to the specification? Why not? See the following list of relevant source code repositories: