An enhanced design and implementation of visual Query by Example that was supported by an AI engine for heuristic, dynamic query optimization.The features that distinguished Paradox/DOS were: Other notable competitors were Clarion, DataEase, R, and DataFlex. At that time, dBase and its xBase clones ( Foxpro, Clipper) dominated the market. Paradox/DOS was a successful DOS-based database of the late 1980s and early 1990s. Version 4.0 and 4.5 were retooled in the Borland C++ windowing toolkit and used a different extended memory access scheme. Versions up to 3.5 were evolutions from 1.0. Notable classic versions were 3.5 and 4.5. In September 1987, Borland purchased Ansa Software, including their Paradox/DOS 2.0 software. The New York Times described it as 'among the first of an emerging generation of software making extensive use of artificial intelligence techniques,' and noted that Paradox could read the competing Ashton Tate's dBase files. Paradox for DOS was a relational database management system originally written by Richard Schwartz and Robert Shostak, and released by their Belmont, California-based company Ansa Software in 1985.
