what is pascal?

Pascal is an imperative computer programming language, developed as a language particularly suitable for structured programming in 1970. Pascal was originally developed to teach programming techniques.
Parts of the original Macintosh operating system were written in Pascal and Motorola 68000 assembly language (though later versions incorporated substantial amounts of C++ as well), and the most frequent high-level language used for development in the early Mac community was Pascal. In addition, the popular typesetting system TeX was written by Donald E. Knuth in WEB, a variant of Pascal designed for literate programming.

• Pascal
• Comparison of programming languages - Wikipedia
• Macintosh