[cultofmetatron]

live view is the original and best.

imitators use long polling to periodically check for updates. liveview spins up a dedicated vm process for each active user and can push updates over websocket to update things. This process can do things like listen for serverside events as well.

[wstuartcl]

It may be redundant but I think its always important to note that processes as listed above are not like os processes here -- but an extremely lightweight internal VM thread like thing in the BEAM VM. In is not uncommon to have many millions running in the beam VM. Very much lighter than threads or OS processes.