Hi Fernando
The best UI technology providing rich UI is HTML5 currently which is supported on all devices and browsers (IE9 is minimum) but with varying degrees of support with Chrome the best but others are not too far behind.
The easiest way to replace the Applets and use HTML5 rendering is to upgrade to MII 14.0 SP4 and use the SAP UI5 based i5Charts, i5Grid.
If you cannot upgrade to MII 14.0 or higher (15.0 has some cool features as well) you may do this on your own where you may use one of several HTML5 based charting libraries like D3, High Charts etc but the work will be more for you as MII 12.2 does not have JSON support (available with MII 14.0 again) and you will have to work with XML or write custom code to convert XML to JSON.
So my suggestion would be upgrade and use i5 Charts as these look much better, are faster and provide almost the same support as the applets. Also these charts would be developed in the future in MII but the applets would remain mostly in maintenance mode. This means new features would, most probably, be only added to the HTML5 charts in MII.
Best Regards
Partha
