Keep multiple browsers & devices in sync when building websites
The DB Browser for SQLite
Jupyter Interactive Notebook
The web-based visual programming editor
Browser-based compiler and IDE
Desktop/Android/HTML5/iOS Java game development framework
Develop desktop GUI applications using PHP, HTML5, JavaScript
The first open source design and prototyping tool
Node library to automate Chromium, Firefox & WebKit with a single API
Offensive Google framework
jQuery Validation Plugin library sources
Javascript Canvas Library and SVG-to-Canvas Parser
Open-source JavaScript library for mobile-friendly interactive maps
Stylus - Userstyles Manager
The original Lightbox script (v2)
Vagrant is a tool for building and distributing environments
A modified browser that helps in responsive web development
The HTML5 Creation Engine
Cybernetically enhanced web apps
A javascript scrollbar plugin which hides native scrollbars
The interactive graphing library for Python
Beautifier for javascript
The plugin-driven server agent for collecting and reporting metrics
Make any web page a desktop application
Javascript audio library for the modern web