MitChart is a project mainly written in ..., it's free.
Javascript's library for charts in canvas
Format and Usage:
var chart = new Mitchart( { 'target': 'div_target_id', 'type': 'chart_type', 'data': { 'y': { 'label': 'label_for_yaxys', 'values': ['jan','fev','mar','abr','mai','jun'] }, 'x': { 'label': 'label_for_xaxys', 'values': [5,2,3,7,1,3] } } } );
chart.plot();