• There are currently six companies listed here, but, the important thing is that the flatpak client software can install things from places other than flathub (and the server-side software running flathub is free software).

          The snapcraft server-side software is closed source, and even if someone reimplemented it they would also need to fork the snapd client software as the snapcraft URLs are hardcoded and not reconfigurable.

            • You could ask on their forum or matrix channel. I just noticed that neither GNOME Foundation nor RedHat are listed on that about page, both of whom iirc are actually very involved. This post says “GNOME has a donor who is interested in supporting financial sustainability for app developers and removing barriers to an inclusive ecosystem. Flathub would like to use these funds to work with a contractor for a short-term project and make steps towards supporting application developers being able to request payments (whether donations or subscriptions).”

              edit: reading more of that thread, I see another recent funder (possibly the aforementioned GNOME funder?) is “Endless Network”… inventors of “The World’s First Pay-As-You-Go PC” 🤦