Hi, Put simply, the Professional edition includes more functionality (such as ad hoc reporting and the ability to save analysis views), and is certified on more platforms than the Open Source edition. For more details, please refer to the Why Choose Professional section of this fact sheet: http://www.jaspersoft.com/JasperSoft_Products.html As to your question about Ad Hoc reporting, it's only offered in JasperSoft's Professional edition. It provides end users with an easy-to-use, drag and drop, web based report designer. Thanks, Kristen