Most of the current Rubicon personnel started with a company in Chicago called Systems Management, Inc. (SMI). SMI was one of the largest sellers of Pick hardware and software in the US and sold an application that ran on Microdata computers under the Pick Operating System (called "Reality").

In 1979, SMI signed a multi-million dollar agreement with one of its largest clients, Plessey Telecommunications, Ltd., of the UK, under which SMI would re-develop its Distribution, Financial, and Manufacturing software in a language and for an environment of Plessey's choosing. Plessey chose Cobol on Prime computers. The project was completed in approximately 18 months. SMI began marketing the product in parallel to its Pick / RPL offering, and made a number of significant sales.

However in 1984, SMI decided to focus entirely on the Pick related market. Five of the members of the Cobol Client Support Group, who had also been involved with the initial design and implementation, decided to start a new company to provide support to the existing SMI customers and negotiated with SMI for the rights to sell and enhance the product. That company is now The Rubicon Group, Ltd.

Today, the code has been rewritten, and significant new features, capabilities, and entirely new modules have been added. Rubicon has ported the Cobol code and runtime utilities to operate in a Unix environment. Since then, there has been a substantial increase in sales, which continues to this day. Today, Rubicon software is running on a wide variety of different platforms, including IBM, Data General, H-P, Intel, Nixdorf, and Pyramid.

SMI has since gone out of business, but Rubicon enjoys a good working relationship with SMI's successor company, Realtime Systems.