FORM is since 27-aug-2010 released under the GNU public license.
In addition we ask you to refer to the FORM publication (J.A.M.Vermaseren "New features of FORM" math-ph/0010025) if you use (T)FORM in scientific publications. The reason is that the development of FORM was paid for by FOM, the Dutch granting agency for physics research and it would be nice if they can trace the importance of the program in scientific work.
Jos Vermaseren, 27-aug-2010