This is a demo WebRTC application for peer-to-peer chat, meaning you don't necessarily need an Internet connection to send messages. It uses the Pusher realtime API for signalling, allowing devices to discover each other and make a connection using WebRTC.

There's a demo showing this in action, as well as a full tutorial on how to create something like this yourself.

You can use any server to pass-through the Pusher messages. This demo provides a few of the most common platforms.

The server code required to run the demo using Node.js.

The src/js/datachannel-demo.js file by default is set up to send AJAX requests to the Node.js server.

You'll need to change the config values in src/_servers/nodejs/config.example.js and rename it to config.js, as well as changing the PUSHER_APP_KEY value in src/js/datachannel-demo.js.

You can then get up and running by running the following commands in the terminal:

$ cd /path/to/your/app/src/_servers/nodejs
$ npm install
$ node app.js

And navigating to http://localhost:5001 to see the side-by-side example or http://localhost:5001/chat.html to see the standalone example.

The server code required to run the demo using PHP.

The src/js/datachannel-demo.js file is not set up to send AJAX requests to the PHP server by default. To enable this you'll need to change the AJAX URL in datachannel.openSignalingChannel to point to _servers/php/message.php.

You'll also need to change the config values in src/_servers/php/config.example.php and rename it to config.php, as well as changing the PUSHER_APP_KEY value in src/js/datachannel-demo.js.

Navigate to http://yourdomain.dev/index.html to see the side-by-side example or http://yourdomain.dev/chat.html to see the standalone example. Obviously you'll need to change the domain to wherever you're hosting the PHP files.

The server code required to run the demo using Ruby Sinatra.

The src/js/datachannel-demo.js file by default is set up to send AJAX requests to the Ruby Sinatra server.

You'll need to change the config values in src/_servers/ruby-sinatra/config.example.rb and rename it to config.rb, as well as changing the PUSHER_APP_KEY value in src/js/datachannel-demo.js.

You can then get up and running by running the following commands in the terminal:

$ cd /path/to/your/app/src/_servers/ruby-sinatra
$ bundle install
$ bundle exec ruby -rubygems app.rb

And navigating to http://localhost:4567 to see the side-by-side example or http://localhost:4567/chat.html to see the standalone example.

It's worth noting that the default PHP server setup in this demo will potentially leave the demo config files for other platforms open to being read. It's highly recommended to implement strict control over which files can be read from your server, or moving the server files into a directory outside of public reach.

When using this demo in your own production environment, you should remove the servers you don't need and ensure that config files aren't readable to the public.