Writing scalable server applications in the Java™ programming language has always been difficult. Before the advent of the Java New I/O API (NIO), thread management issues made it impossible for a server to scale to thousands of users. The Grizzly framework has been designed to help developers to take advantage of the Java™ NIO API. Grizzly goals is to help developers to build scalable and robust servers using NIO and we are also offering embeddable components supporting HTTP, Bayeux Protocol, Servlet (Partially) and Comet

Atmosphere is a POJO based framework using Inversion of Control (IoC) to bring push/Comet to the masses! Finally a framework which can run on any Java based Web Server, including Tomcat,Jetty, GlassFish,Resin, Jersey,RESTlet etc….. without having to wait for Servlet 3.0 or without the needs to learn how push/Comet support has been differently implemented by all those Containers.