Stallman stepped down from his post in 2019, following remarks he made about the victims of the late Jeffrey Epstein, an American financier and convicted sex offender.
But at the FSF's annual LibrePlanet conference on 19 March, he announced that he would be returning to the board and would not resign again.
This, predictably, sparked a reaction and there have been calls for FSF patrons to stop supporting the foundation.
"These sorts of beliefs have no place in the free software, digital rights, and tech communities. With his recent reinstatement to the Board of Directors of the Free Software Foundation, we call for the entire Board of the FSF to step down and for RMS to be removed from all leadership positions."
I'm stepping away from GnuPG. I never had any particularly important official position with them, but I did have git commit rights and was kind of proud of that. My reasons are here. pic.twitter.com/jp7X5Eahhw— Robert J. Hansen (@robertjhansen) March 23, 2021
Among those who appended their signatures were Google's Chris DiBona, Linux System Administrators' Guide author and veteran developer Lars Wirzenius, GNOME project co-founder Federico Mena Quintero, former Debian leaders Neil McGovern, Stefano Zacchiroli and Steve McIntyre, and a number of Debian developers, among others.
On Tuesday, Robert Hansen, a contributor to the GnuPG encryption software project, said he was stepping away, citing Stallman's return to the board as the reason.
"I'm not leaving the mailing list. I'm not leaving the community. You'll continue to see me around," he said.
"And, should Richard Stallman resign or be removed from positions of influence in the FSF and the FSFE [Free Software Foundation Europe], I will be happy to pick up the FAQ maintainer role again."
The letter added: "We urge those in a position to do so to stop supporting the Free Software Foundation. Refuse to contribute to projects related to the FSF and RMS.
"Do not speak at, or attend, FSF events, or events that welcome RMS and his brand of intolerance. We ask for contributors to free software projects to take a stand against bigotry and hate within their projects. While doing these things, tell these communities and the FSF why."
The remarks that led to Stallman quitting in 2019 were made on an MIT mailing list, where he said the term sexual assault "is so vague and slippery that it facilitates accusation inflation: taking claims that someone did X and leading people to think of it as Y, which is much worse than X".
His reference was to deceased AI pioneer Marvin Minsky who was accused of assaulting one of Epstein's victims, Virginia Giuffre, who was 17 at the time. Epstein committed suicide while in jail for alleged child trafficking offences.