In theory, there’s a wide choice of software. As well as Flatpaks, Vanilla OS also has built-in support for Alpine, Debian, Fedora, Arch, and openSUSE packages via its own package-management wrapper called Apx… and it also claims support for the AppImage format, and an Android runtime based on Waydroid.
However, we couldn’t get anything except Debian packages working in our testing.
this is a very bleeding-edge experimental distro, and in practice, we found it felt unfinished and not fully working.