FYI these packages are maintained by the .NET toolchain team at Canonical, which I'm part of. We build and publish every .NET servicing release as they come and security updates are pushed at the same time as Microsoft so that no one is zero-dayed.

Have fun and feedback is welcome! 🎉

We maintain a backports package repository where we publish .NET versions to Ubuntu releases that don't have them by default.

If you're on 24.04 (Noble Numbat) or 22.04 (Jammy Jellyfish), you can run:

$ sudo add-apt-repository ppa:dotnet/backports
$ sudo apt install dotnet9

Almost a year ago, that's crazy!