Extjs-grid-simple-array is a project mainly written in JavaScript, it's free.
ExtJS Grid with Simple Array
Getting started with Ext JS Datagrid Link:
Portuguese translation of this tutorial:
To execute this project: http://localhost:8080/extjs-grid-simple-array/
Blog: http://www.loianegroner.com
My Pt-Br Blog: http://www.loiane.com