From GNU lists earlier today:

We have learned with deep sadness that Thien-Thi Nguyen (ttn) died in October 2022. Thien-Thi was a hacker, artist, writer, and long-time maintainer and contributor to many GNU programs as well as other free software packages. He was the GNU maintainer of the rcs, guile-sdl, alive, and superopt packages, and he was working on GNU Go as well.

Thien-Thi especially loved GNU Emacs, GNU Taler, and GNU Go: he was the author and maintainer of the xpm, gnugo, ascii-art-to-unicode, and hideshow GNU Emacs packages and made substantial contributions to many others such as vc, as well as to GNU Taler and its documentation.

We greatly miss Thien-Thi in the free software community - his death is a great loss to the Free World.