Cactus code is expected to be LGPL (or more freely I guess) licensed. Initially what was used was GPL with a an exemption:
This thorn is (c) Copyright the authors listed in the sources files. This
thorn is distributed under the GNU GPL with the specific exception that
the GNU GPL does not migrate to code linking to or using infrastructure
from this thorn.
- The Cactus Team firstname.lastname@example.org
eg in cactusbase/Boundary. This was then changed to be LGPL (which amounts to the same exemption) around 2009 and also around 2015 (see eg commit logs in cactus* repos).
However some repos were missed and either show no license information at all in README or have LGPL (in the README file) but the GPLv2 COPYING file (with or without the manual exemption). Affected is eg Formaline which lists no license in its README file, but has a commit 5de0764 "Formaline: Make Formaline GPL." of cactusutils declaring it GPL.
To change license, one actually needs permission from all copyright holders. For Formaline the list of authors (but not necessarily copyright holders, that may actually be the respective universities and employers) is:
Steven R. Brandt
but not all can be asked for permission anymore.