Twitch is a Popular Game Streaming Service, and they have an extensive API that allows users to interact with their streams, and services.
This PHP Twitch API Script was created in 2013, and runs sites such as http://runescapestreams.com/, http://minecraftstreams.com/, and many more. This Live Stream PHP script is a good Twitch API example for newbies, and a good library for to extend websites for developers, and site owners.
With this script, you can pull Twitch Streams by game, users, and many other attributes. This is a great added feature if you want to add live streams to your website.