GSH builder is a free Galois Sub-Hierarchy visualization tool.
The algorithm for calculating GSH is called Pluton and the present
Java realization is based on two articles.
"Efficiently computing a linear extension of the sub-hierarchy of a
Concept Lattice" by Anne Berry, Marianne Huchard,
Ross M. McConnell, Alain Sigayret and Jeremy P. Spinrad.
"Performances of Galois Sub-hierarchy-building algorithms" by
Gabriela Arevalo, Anne Berry, Marianne Huchard,
Guillaume Perrot and Alain Sigayret
In you're in need of other GSH algorithms or their realizations in C++,
you might want to investigate a project called Galicia on sourceforge.
This program is free software and is licensed under GNU General Public License
as published by the Free Software Foundation.
Only jre7 compliant at the moment.