CSLA .NET is a software framework created by Rockford Lhotka that provides a standard way to create robust object oriented programs using business objects. Business objects are objects that abstract business entities in an object oriented program. Some examples of business entities include sales orders, employees, or invoices. Although CSLA itself is free to download, the only documentation the creator provides are his books and videos, which are not free. Current information about CSLA .NET is available through Lhotka's self-published Using CSLA 4 ebook series.