Today I will overview two Linux games which are a very good alternative to the famous Civilization series from Windows, Freeciv and FreeCol. They are both open-source, free, and usually come included with every distribution.
Freeciv is based on the client/server model, so the server is started automatically when you start a new game. It provides two different client interfaces: GTK2 and SDL (see below on how to install and launch).
To install in Ubuntu, type in a terminal either one of the following commands:
sudo apt-get install freeciv-client-gtk2 # (for the GTK client) sudo apt-get install freeciv-client-sdl # (for the SDL client)
To launch the game, press Alt+F2 and type freeciv in the run dialogue that appears or go to Applications->Games->Freeciv. If you installed both packages (even though there is no need to do it), to launch it either type freeciv-gtk2 or freeciv-sdl.
Starting a new game
The SDL client allows you to run the game in window mode and fullscreen and to change the resolution.
GTK2 client - in-game screenshot
FreeCol is written in Java, so it has a slower interface, but other than that, it looks and behaves great. Freecol resembles the Colonization game, under the slogan 'the Colonization of America' but having better graphics and being actively developed. FreeCol runs in fullscreen but it doesn't steal control from the window manager, so it allows you to use Alt+Tab in order to access your other opened applications.
Installation in Ubuntu. Just type sudo apt-get install freecol in a terminal. The version included in the Maverick Beta repositories is 0.9.2.