The Windows and Mac versions shared a different codebase that was based on In-House Accountant, which Intuit had acquired. The initial release of QuickBooks was the DOS version that was based on the Quicken codebase.
The initial Quicken software did not function as a ' double-entry' accounting package.
After the success of Quicken for individual financial management, the company developed similar services for small business owners. Intuit was founded in 1983 by Scott Cook and Tom Proulx in Mountain View, California, USA.
