Day 44: The windows are watching. Every reflection is a door. Day 47: I broke one. Never break one. The thing on the other side—it’s been exiled. It needs a host. A point of view. Day 48: If you read this, don’t look at any glass. The stalker is the window. The player is the pawn. The windows are the board.

Because Windows does not have a "native" Stalker client built-in, users typically rely on dedicated desktop apps or emulators.