Here are 4 open-source packers, written in Delphi (you can convert to C++ if you want):

  1. ExeFog 1.1
  2. Polymorphic Crypter, Morphine
  3. AHPacker 0.1
  4. GHF Protector 1.0

If you don’t have a copy of Delphi, you can use the open-source Lazarus IDE with the Free Pascal (FPC) compiler.

Lazarus + FPC can open Delphi project files and can usually compile Delphi projects without modification: