4Q is specially engineered to support the development of custom software using the 4th Dimension® (4D) database environment. 4th Quarter’s patented "accounting engine" provides GL, AR, AP, Checking, Order Entry, Inventory, Financial Reporting, DB Administration, and Payroll functions to any custom-written 4D-based business application.

The 4th Quarter family of products include 4Q Shell, 4Q Core, 4Q Full, and 4Q Job Costing. All versions run “out of the box,” without modification, on Mac and PC systems. Source code is available.