Xconq

Xconq is an open-source computer strategy game. First posted to comp.sources.games on 9 July 1987, it is notable as one of the first multi-player games to be released for the X Window System. It was for several years the only turn-based graphical war game available on Unix/X systems.
Xconq is released as free and open-source software under the terms of the GNU GPL-2.0-or-later.
Gameplay.
Originally a straightforward clone of "Empire", later versions included the ability to define rulesets for different kinds of games, first using a Forth-like syntax, then a more powerful version based on Lisp syntax. It was also ported to other computer systems, including Macintosh, Amiga, and Windows.
"Xconq" is designed to be portable and re-definable. The default rule set is similar to "Empire", but the rule set, graphics and maps can be altered to represent different time periods and strategic scales.
Example rule sets provided with the game include Napoleonic strategy, Beirut guerilla fighting, World War II grand strategy and Godzilla destroying Tokyo.
It can be played by multiple human or AI-controlled players over a network or via hot seat play.
History.
Stan Shebs started working on a simple "Empire" clone in 1986, initially using Curses for its interface, then adding an X10 interface. He posted this version to comp.sources.games in July 1987. It used a map based on squares rather than hexes, and supported multiple players by exploiting X's capability for a single program to open windows on multiple displays, although it accepted input from only the player whose turn it was; other players could not even scroll their map display. Even this first version included support for three rulesets (the "standard" Empire-like game, a Napoleonic-era game, and ancient Greeks), but they were defined by C structures and had to be compiled in.
Shebs switched the game to use hex-based maps, added a postfix language to define the ruleset to be used when a game started, and changed the X interface to allow all players to interact simultaneously; these versions were numbered 2, 3, and 4, but were not released widely. After the addition of an X11 interface written by Chris Peterson, version 5.0 was posted to comp.sources.games (as "xconq5") in June 1988.
1989 saw the first attempt at a client/server version, "uconq".
The Macintosh port was developed in 1993.
Although work had started on version 7.5, there has been little development since 2004, with the last CVS commit made in 2007.