On Linux, there are two problems with Steam after the initial install:
- It always opens its window on startup.
- If you you close it under some window managers, like KDE, it just minimizes to the panel instead.
To correct both issues, open up the desktop shortcut in your favorite editor:
sudo gedit /usr/share/applications/steam.desktop
Now, find the line that says:
and change it to:
Exec=env STEAM_FRAME_FORCE_CLOSE=1 /usr/games/steam -silent %U
Save the file, and restart Steam.
The “-silent” parameter will cause Steam to launch mimimized to the panel, and the “env STEAM_FRAME_FORCE_CLOSE=1” portion will make the close button actually close to the tray instead of minimizing to the panel.