Note on the different versions
Liquid War is a game. A game in constant evolution (yes, slow, but constant).
Version 5 is stable, available since 1998, distributed by Debian, Mandriva, available for Microsoft Windows, Mac OS and FreeBSD. It has the great advantage to just work, but it's getting old, and it's hard to maintain.
Version 6 is more recent (logic!) but less stable (logic too!). However, it's playable, I suggest you give it a try.
Version 3 is a dead branch, too old and crappy to run on any recent computer, but it's still there.
That's it.