[FlyingMongoose]

To point out, this does not actually restart the server unless you fall under one of a number of conditions.

On *nix your server is set to a daemon that keeps the task running and if it finds it closed launches it again
On Windows, your server is launched via a batch file that keeps the task running and if it finds it closed launches it again
On Windows, your server is launched via a server checking utility which keeps it running and if it finds it closed launches it again.
If you are on a server provider, any one of these could be the case and this plugin should work fine for you, however, if you do not, and do not have one of the above listed possibilities all this will do is periodically close your server.