There are 2 file types use the .PAS file extension:
1. Delphi Unit Source File
Source code file created in Delphi, a software development application used for building Windows programs; written in the Delphi language, which is a variant of the Object Pascal language; can be compiled into native Win32 code with the Delphi compiler.
PAS files are used as the primary source code format for Delphi.
Updated: August 6, 2013
2. Pascal Source File
Program file that contains source code written in Pascal or Object Pascal, two general purpose high level programming languages; can be edited with a Pascal development program or a basic text editor.
PAS files can be compiled into executable programs using a Pascal compiler such as Turbo Pascal.
Updated: March 24, 2013