This is a Play application that allows you to use your browser to interact with an instance of classic NetLogo that is running on a server.
Related is NetLogo Web (formerly known as "Tortoise"), which is a JavaScript-based version of NetLogo that runs entirely in the client's browser. NetLogo Web can most easily be used through through the Galapagos web application.
For more information about the Tortoise project in general, see here.