A method of selling custom business software and a software exchange marketplace enables a software seller to offer a custom software application for sale. The method includes receiving the custom software application from the software seller. The marketplace includes a qualified application inventory and a custom software application submission log. A prospective software buyer may search the qualified software application inventory. The method includes associating the custom application with the custom software application submission log. The method identifies deficiencies with a software source code by comparing the software source code to a source code qualification standard. The method identifies deficiencies with a plurality of software documents by comparing them to a document qualification standard. The method compares the submission log with a final review standard. The method qualifies the software source code and software documents before listing them in the qualified software application inventory.