When I was finished setting up my neatly configured environment (grizzly, jersey, filters, static resources, …) I got annoyed when I started to work on the frontend. When the Grizzly server was running and e.g. the index.html was called, then there seems to be a file lock on that file. This prevents me from making changes to it so that I would have to stop the server, save the file and start the server to make the changes visible. This is no fun when developing!