yes and no? Unlike a traditional daemon, this isn't a system service that always runs in the background.

The IDE (in this case atom) spins up the process and shuts it down when necessary, and then both sides communicate to each other using an implementation-defined IPC mechanism.

So it's a server more in the sense that the IDE requests info as a client, and then the server provides it (pull, not push).

yes. They are deamons which are spawned by the editor and which are running locally on the machine. The daemons are reapsonsible for analyzing code in the edited project and to provide IDE-like features (auto-completion, refactorings, etc.) around it. The editor talks to the daemon (language-service) through an RPC protocol (language server protocol).