The Orbifolder: A Tool to study the Low Energy Effective Theory of   Heterotic Orbifolds
  The orbifolder is a program developed in C++ that computes and analyzes the low-energy effective theory of heterotic orbifold compactifications. The program includes routines to compute the massless spectrum, to identify the allowed couplings in the superpotential, to automatically generate large sets of orbifold models, to identify phenomenologically interesting models (e.g. MSSM-like models) and to analyze their vacuum-configurations. 
Hans Peter Nilles, Saul Ramos-Sanchez, Patrick K.S. Vaudrevange, Akin   Wingerter
hep-th hep-ph physics.comp-ph