The title is a bit hyperbolic, true. There have been various ways to try to contain desktop apps over the years. But I wouldn't call them "apps" really, they ma

The title is a bit hyperbolic, true. There have been various ways to try to contain desktop apps over the years. But I wouldn't call them "apps" really, they may get the sandboxing aspects down, but they don't have the simple-to-install, well-integrated behaviour that you'd want for something like an "app" system. Most of them basically run the app in its own VNC or Xserver instance, with zero interaction with the rest of the session.