Tornado vs. Dropwizard vs. Cocoa (OS X)

By using non-blocking network I/O, Tornado can scale to tens of thousands of open connections, making it ideal for long polling, WebSockets, and other applications that require a long-lived connection to each user.

Dropwizard is a sneaky way of making fast Java web applications. Dropwizard pulls together stable, mature libraries from the Java ecosystem into a simple, light-weight package that lets you focus on getting things done.

Much of Cocoa is implemented in Objective-C, an object-oriented language that is compiled to run at incredible speed, yet employs a truly dynamic runtime making it uniquely flexible. Because Objective-C is a superset of C, it is easy to mix C and even C++ into your Cocoa applications.