Money.js
money.js is a tiny (1kb) javascript currency conversion library, for web & nodeJS
Springy
A force directed graph layout algorithm in JavaScript
LScache
A localStorage-based memcache-inspired client-side caching library.
Timesheet.js
JavaScript library for HTML5 & CSS3 time sheets
Ydn Db
Javascript database module for Indexeddb, Web SQL and localStorage storage mechanisms supporting version migration, advanced query, SQL and transaction.
Local Storage
A localStorage polyfill
Fuse
Lightweight fuzzy-search, in JavaScript
Backgrid
Finally, an easily stylable semantic HTML data grid widget with a Javascript API that doesn't suck.
jQuery treetable
jQuery plugin to show a tree structure in a table
Tabletop
Tabletop.js gives spreadsheets legs
JSON.js
JSON in JavaScript
Flotr2
Graphs and Charts for Canvas in JavaScript.
Dgrid
A lightweight, mobile-ready, data-driven, modular grid widget designed for use with the Dojo object store
Convnetjs
Deep Learning in Javascript. Train Convolutional Neural Networks (or ordinary ones) in your browser.
Slick Grid
A lightning fast JavaScript grid/spreadsheet
Flot
Flot is a pure JavaScript plotting library for jQuery, with a focus on simple usage, attractive looks and interactive features.
Faye
Simple pub/sub messaging for the web