We are excited to announce FillPDF LocalServer, a replacement for the current Java servlet that uses PHP/JavaBridge.
It uses Docker, meaning that it's fairly easy to set up regardless of platform. You only need to be able to install Docker.
Rather than the Drupal module accessing it over shared message passing, it provides a modern REST API. The updated Drupal modules simply make HTTP requests to this and process the result. It is nice and fast.