Technote: EXE Packers

Recently on the FreeDOS mailing list, there was a discussion that eventually lead to EXE packers for DOS. I am reproducing that part of the discussion here, as the topic seems to come up from time to time:

Ralf Quint writes:

Well, i am not comletely sure if i understand you right, but i would like to note the following:

- The program you are referring to ["... how about compressing the files with pkzip (there is a version that compresses an EXE/COM) ..."] is called PKLite and is payware, so you can't use it for a project like FreeDOS

- There are free EXE-Packers available, like APACK which is free for non-commercial apps or UPX which is available under he GPL with a special license that allows it to be used for commercial apps as well.

Owen Rudge adds:

UPX is now at, BTW. I highly recommend it.

And Ralf points out:

To quote from the SF page ;-)):

The UPX project has not yet completely moved to SourceForge - please go to the old pages at in the meantime.

Marco van de Voort adds:

Also mention strip (see DJGPP and FPC) [...] They are not real exe-packers, but are often conceived by users as such.