This is Patrick Pélissier's archive pack unpacker. It is needed to unpack kernel-based archive packs so they can be patched with GhostBuster. It is part of PreOs:

  PreOS -Kernel Extender for Ti-92+, Ti-89 & V200 systems- 
  Copyright (C) 2003 Patrick Pelissier
  
  This program is free software ; you can redistribute it and/or modify it under the
  terms of the GNU General Public License as published by the Free Software Foundation;
  either version 2 of the License, or (at your option) any later version. 
  
  This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
  without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  See the GNU General Public License for more details. 
  
  You should have received a copy of the GNU General Public License along with this program;
  if not, write to the 
  Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA