Serenade.js is a dependency-free MVC framework with a powerful templating language, as well as powerful caching features and dependency-free functioning at a mere 9kb.

// templating markup in Serenade is pretty impressive:

<h1 title="Jonas">His name is Jonas</h1>

Serenade is quite similar to backbone.js in the way it works; however, as the developer explains, the original MVC approach is used. Thus, the controller’s sole purpose in Serenade is responding to user events.

Although the framework doesn’t provide a routing system an external one can be implemented, especially given that Serenade’s dependency-free nature won’t interfere with other libraries you want to use.

• Website: https://github.com/elabs/serenade.js

Gerbil is an “uber simple and minimalistic” testing framework for JavaScript.

Gerbil allows testing units without the aid of a browser; the results are shown in the console.

This framework is a lightweight solution for testing functions and function chains in different scenarios. It’s easy to use and does the job, which is just what every decent gerbil does.

• Website: https://github.com/elcuervo/gerbil

Vesper is a Ruby framework designed for clarity, flexibility, and effectiveness.

Vesper is built on top of Sinatra — in its core, Vesper is a ready-made Sinatra app with less configuration needed, and reduced weight.

The framework comes with several plugins loaded. CoreExtender, DataMapper, and PonyMail are several of them.

Vesper is particularly appealing to non-programmers, because Vesper’s plugins are much easier to add and configure than Ruby gems.

Of course, Vesper supports Ruby gems, too.

• Website: http://vesperapps.com/

Spark is a Java micro framework for creating web applications with minimal effort.

Spark is similar to Sinatra in terms of structure, but is instead meant for developers who want to develop in pure Java. (Sinatra runs on Ruby.)

Spark, unlike many similar frameworks, doesn’t require XML configuration, and altogether tries to provide a framework for rapid app development in a clean environment.

The framework has a basic routing system and offers a number of useful methods (that are rather common in other frameworks, too) for building RESTful web applications.

• Website: http://www.sparkjava.com/

Crafty is a JavaScript game engine with an emphasis on browser compatibility and coding simplicity.

What’s great about Crafty is its core simplicity that allows for a lot of reusable code: objects are treated as entities, but functions are treated as components, and, as you might guess, you can add a component to more than a single entity.

The game engine has great collision detection features, and some of the demo games are quite impressive — do check them out!

• Website: http://craftyjs.com/
• Demo: http://craftyjs.com/demos.php

Brunch is a lightweight framework for building HTML5 web apps.

Brunch is standing on the shoulders of giant JS libraries (Underscore, jQuery, CoffeeScript, etc.), and gives developers the freedom to use their own dependencies.

Upon building, Brunch concatenates  the dependencies into a single JavaScript file, and, together with its command line, is a tool that’s rather convenient for making smaller apps.

• Website: http://brunch.io/