A fresh approach to AJAX that speeds up web applications. Progressive JSON parser with an easy interface so you can use the objects before the http response completes.
Peer-to-peer data in the browser
Alchemy.js is a graph drawing application built in d3.
jQuery Gantt Chart
Version 2 of Polychart.js
Awesome charts for AngularJS.
Multi-database ORM: redis, mongodb, mysql, sqlite, postgres, neo4j, memory... Many databases, common API.
Pretty time-series line graphs