For JavaScript and AJAX applications, Taffy DB is a beautiful tool.

Taffy DB is an open source JavaScript library that acts as a data layer inside the applications. Just think of it as a SQL database in your web browser.

Let’s say you have a collection of products and you want to find every product that costs less than $10 and is not a book. Simple, just write some JavaScript:
products.find({price:{lessthan:10},
type:{not:"Book"}});

Major features:

• Under 10K!
• Simple, JavaScript Centric Syntax
• Fast
• Easy to include in any web application
• Compatible with major Ajax libraries: YUI, JQuery, Dojo, Prototype, EXT, etc
• CRUD Interface (Create, Read, Update, Delete)
• Sorting
• Looping
• Advanced Queries

Check out the Getting Started Guide for Taffy DB’s capabilities.

Ext JS LiveGrid component, a component for the powerful Ext JS Framework, makes it easy to create non-refreshing, live grids.

This EXT JS component is very handy while browsing through a large amount of data as all data doesn’t need to be loaded once & no need for paging.

Google Charts API (previously described here) is so easy to use. Just adding parameters to the API URL & that’s it.

If you ever wondered how easier it could be, than ChartMaker, which is an interface that creates the Google Charts API URL with the parameters that you mention, is the answer.

ChartMaker is built with the Ext JS Javascript library and is an open source code which is created by Dion Almaer (also the founder of Ajaxian).

To read the hard & complicated (a funny story) creation process of ChartMaker, click here.