Pascal is an influential imperative and procedural programming language, designed in 1968–1969 and published in 1970. Borland's Turbo Pascal, and the later Borland Pascal, were popular in the 1980s and early 1990s on the PC/MS-DOS platform (CP/M versions were also released).
Another popular version of Pascal in the late 1970s and early 1980s was the UCSD p-system, which compiled Pascal to platform-independent pseudocode called p-code and had its own custom operating system and file system.
Its popularity is greatly reduced in recent years, probably to some extent due to the fact that most current programming languages adopted syntax based more on C than Pascal, so the syntactic features of Pascal, such as the use of = for comparisons and := for assignments, and the begin/end keywords marking code blocks, are unusual to programmers more used to the C conventions of = for assignment and == for comparison, and curly braces for code blocks.
See also Object Pascal.