Tim Mattingly and Tom Friedman, the developers of Plus & Minus, started their accounting careers on a crane company audit in 1973.  The company had two domestic subsidiaries and a foreign subsidiary.  The books were kept by hand, written in ink, by a German controller and one assistant.  It was a work of art.  There were journals recording the original source documents, general ledgers with journal postings, and subsidiary ledgers for receivables, payables, and fixed assets.  They created working trial balances, which were the foundation for the final consolidated financial statements.  The crane company books were a real-world application of Luca Pacioli’s double-entry bookkeeping treatise published in 1494.

Five years later, Tim and Tom had the opportunity to convert a Honeywell mainframe accounting tape system to disc.  The Honeywell system was transaction based and very rudimentary in reporting.  Honeywell abandoned the project before finishing; however, they could see the possibilities and began to realize that it was possible to perform all functions in one data set.

In 1982, work began on an Apple III.  The developers agreed on a basic format and started writing.  Within a few months, a basic system was running to handle a construction company.  The system could produce aged account payables, write vendor checks, and produce an income statement by job comparing actual results against a budget.  The following year, a mortgage company paid the developers to convert the system to a Microsoft-based operating system.

Over the years, the company grew with more customers, user groups, and support staff.  In 2000, the developers sold the company to an investor group.  The terms of the sale allowed the developers to keep and maintain Plus & Minus for their own use and a select group of companies.  Then in 2010, the developers purchased Plus & Minus back and picked up where they left off.

Today, Plus & Minus is owned by the developers without interference from investors.