Here are resources to help you get started with Cettia:
An introductory tutorial to Cettia. It explains the reason behind key design decisions that the Cettia team have made in the Cettia, as well as various patterns and features required to build real-time oriented applications without compromise with Cettia.
Otherwise, if you want to see Cettia in action first, run the Cettia starter kit which is based on Servlet and Java WebSocket API.
Cettia Java Server
A simple and scalable Java server designed to run Cettia applications on any platform on the JVM.
A reference implementation and test suite for Cettia protocol.
A lightweight abstraction layer for Java web frameworks to build web framework-agnostic applications like Cettia.