FitSuite is a scientific software provided free as it is under the terms of GNU GPL license, except for one additional condition: should you use FitSuite to any extent for your publication, you should cite the article on FitSuite currently available at http://arxiv.org/abs/0907.2805v1, by mentioning also the name of the program and the version number. (e.g.: FitSuite 1.0.4) The above link will be updated when the regular journal article will be out. Please use to Forum to disseminate the bibliographic data of your published papers that make use of FitSuite.
Fitsuite uses the open source version of Qt4 (Qt4 licensing).
Source code of the main program is available on personal request to the author: (szilard @ rmki.kfki.hu ), since it is essential for us and our funding agencies to keep track of the distribution. Source code of the routines of the theories are already included in the binaries.