HEVEA home page is http://hevea.inria.fr/. It contains links to the on-line manual and to the distribution.
The author can be contacted at Luc.Maranget@inria.fr.
HEVEA can be freely used and redistributed without modifications. Modifying and redistributing HEVEA implies a few constraints. More precisely, HEVEA is distributed under the terms of the Q Public License, but HEVEA binaries include the Objective Caml runtime system, which is distributed under the Gnu Library General Public License (LGPL). See the LICENSE file for details.
The manual itself is distributed under the terms of the Free Document Dissemination Licence.