A Todo app in 30 lines

PsychoPy is an open-source application to allow the presentation of stimuli and collection of data for a wide range of neuroscience, psychology and psychophysics experiments.

A dead-simple way to generate dynamic bits of HTML and add subtle effects to your content

By Keith Jenkins/NPR.

FACTORIE is a toolkit for deployable probabilistic modeling, implemented as a software library in Scala. It provides its users with a succinct language for creating relational factor graphs, estimating parameters and performing inference.

React is a platform built on PHP for easily building fast, scalable network applications. React uses an event-driven, non-blocking I/O model that makes it lightweight and efficient, perfect for data-intensive real-time applications that run across distributed devices.

Google Analytics Setup and Configuration Tool

This project won't seek to provide a perfect solution to every possible pattern, but will attempt to cover a simple template for beginners and above. By using a basic defaults object, simple constructor for assigning the element to work with and extending options with defaults and a lightweight wrapper around the constructor to avoid issues with multiple instantiations.

https://www.facebook.com/dialog/pagetab?app_id=YOUR_APP_ID
&display=popup&next=YOUR_URL

The usual toolbox, plus good suggestions in the comments.

A shell to extend the Java Platform

Detailed example of building a widget in a new GUI framework based on channels and goroutines. Extensive use of goroutines for communicatio of settings and properties.