WASHINGTON--(BUSINESS WIRE)--Arlington Capital Partners ("Arlington Capital"), a Washington, DC-based private equity firm, today announced the acquisition of Ontario Systems ("OS"). OS is a market leading provider of revenue cycle management (“RCM”) software and solutions to healthcare providers, outsourced RCM and accounts receivable management (“ARM”) firms, and government clients. For more than 30 years, Ontario Systems has served healthcare providers and their business offices with software