Website: http://grappl.io/

Donations: http://grappl.io/donate

Launcher: http://grappl.io:888/html/GrapplLauncher.jar (Beta 1.1 currently, autoupdates)

Relay server code: https://github.com/Cactose/GrapplRelay

Grappl is a tool for hosting servers behind closed ports. People connecting don't have to download anything to connect to Grappl'd servers, unlike with other programs such as hamachi.

All you have to do to run it is run the .jar, choose whether you want to be logged in or anonymous, specify what port your server is bound to, and your server will be open for anyone to connect. No messing around with port forwarding.

It works by transferring data through relay servers on grappl.io.

The project is in beta. This repository contains all the newest client code.

Using Grappl's client API is very simple and straightforward.

Just create a GrapplBuilder, use the supplied methods to configure Grappl's state, then use build() to create the Grappl object. Like so:

Grappl grappl = new GrapplBuilder().atLocalPort(25565).build();

After that, use the grappl object's connect method to open the server.

grappl.connect(relayServerIP);

'relayserverIP' is a string representing the relay server of your choice. This may be one of the official ones (n.grappl.io, s.grappl.io, e.grappl.io, p.grappl.io) or a custom one.

grappl.getPublicAddress();

...will give you the address that your server is now live on the internet behind! Congrats, you've got Grappl working through its API. It's that simple.

The Grappl code is released under LGPL v2.1.

Grappl is primarily developed by Matt Hebert.

His twitter is here: https://twitter.com/Cactose