Task: Question Generation
Input (English): Context : XPL0 is a computer programming language that is essentially a cross between Pascal and C. It was created in 1976 by Peter J. R. Boyle who wanted a high-level language for his microcomputer and wanted something more sophisticated than BASIC, which was the dominant language for personal computers at the time. 
Subject : XPL0 
Relation : based on
Output (English): Which is the basis of XPL0?