D3.js (D3 for Data-Driven Documents) is a JavaScript library for producing dynamic, interactive data visualizations in web browsers. Developed by Mike Bostock
License: Open Source
Raphaël is a simpler library focused on creating vector graphics with ease of use, making it suitable for straightforward projects, while D3.js is a powerful tool designed for complex data visualizations and data-driven documents, offering extensive customization and interactivity.