Ale Halt; si po sebe neuprace. Korektné je len Application.Terminate;. Halt je na použitie vhodný vtedy, ak je program "načatý" nejakou chybou a nedokáže sa "spamätať" a potrebuješ vrátiť riadenie systému. Napríklad nabúraš pamäť a pokračovanie programu nie je vhodné.

Edit:
Halt performs an abnormal termination of a program and returns to the operating system.

To perform a normal termination of a Delphi application, call the Terminate method on the global Application object. If the application does not use a unit that provides an Application object, call the Exit procedure from the main Program block.

Exitcode is an optional expression that specifies an exit code for the program.