What do you use to make chart?

If I am not mistaken the example you posted can be done in Numbers (iWork)…

Makes beautiful charts and graphs for me — "efficiently".

 

Excel is surprisingly competent when it comes to making graphs.

Not great.

Just competent.

 

No spreadsheet application can approach the quality of charts that you can make by hand using Illustrator. For this, you should use a dedicated charting application. The dedicated charting application that meets your needs is DeltaGraph.

 

Basically, it's iWork. That is what the creator of that chart used. You can get a demo from http://www.apple.com/iwork/

Here is a fictional chart I prepared with it:

 

My wife teaches statistics, and I've considered building her an AIR application that constructs bar charts from data input.
Seems like it would be fairly straightforward to set up using an XML document as the data source.