Microsoft Pascal

Microsoft Pascal was an implementation of the Pascal programming language that was developed by the Microsoft Corporation for compiling programs for running on its MS-DOS operating system and, in later versions, on OS/2 (like many other Microsoft programming tools, albeit they were only capable of generating 16-bit programs for the latter).

Microsoft Pascal version 3.2 was released in 1986. The last version of Microsoft Pascal to be released was version 4.0 in 1988, when Microsoft Pascal was superseded by (the somewhat short-lived) Microsoft QuickPascal, a cheaper development tool that Microsoft produced in order to compete with Borland's Turbo Pascal. Microsoft Pascal was priced at around $400, whereas QuickPascal was priced between $25 and $50, and the differences between the two were similar to those between Microsoft BASIC Professional Development System and Microsoft QuickBASIC.

Unlike the ISO compliant Microsoft Pascal product, QuickPascal went after the ultimate compatibility with Turbo Pascal. This included not only source-level compatibility, but rather complete binary compatibility with widely available unit libraries for the competitor's compiler. To achieve this level of compatibility, QuickPascal moved away from the common file format (OBJ) and tool set (LINK, LIB) shared by Microsoft's other compilers.

It is interesting to note that Borland's Turbo Pascal V4 had a few quirks, the most notable of which was that it would occasionally ignore one or more lines of source code when said code was compiled. QuickPascal had exactly the same quirks and ignored exactly the same lines.