QuickBASIC is an implementation of BASIC with a decent built-in editor. It was extremely popular among amateur game programmers in the DOS days, and still has a die-hard loyal following, in spite of its severe memory limitations (16-bit real-mode memory model)
The OHRRPGCE was written in QuickBasic because that was the only language James Paige knew in 1997. The code has since been ported to FreeBasic and QuickBASIC support has been dropped. It is also being rewritten in other languages.