The www.gtkmm.org website has not been updated for
a long time. There are a number of gtkmm issues about obsolete
information. I don't know
how to update the website. The source code is stored at https://gitlab.gnome.org/GNOME/gnomemm-website.
I've made a few updates to the source code, and used GitLab's
CI and Pages to have a partially updated version published at
https://gnome.pages.gitlab.gnome.org/gnomemm-website.
That's not good enough. No one will find it there. Who has
permission to update www.gtkmm.org?