sysUtils shipped with the FPC’s default run-time library provides a plethora of system utilities.
It attempts to be as compatible to Delphi’s
sysUtils unit as possible.
However, the FPC version is available on all platforms the FPC supports.
You will not find any Windows-related routines or other highly platform-specific functionality.
sysUtils unit is included, all run-time errors become exceptions, thus virtually forcing you to use a compiler mode (or mode switch) that allows exception treatment.
You will need to include
sysUtils in every unit that may throw an exception just to familiarize with the exception classes, even though the unit itself does not use any actual code of it.