About
Ares is a game developed by Nathan Lamont and released for classic Mac OS in 1998. It was later re-released and expanded with plug-in support by Ambrosia Software, then fell into obscurity after not being ported to Mac OS X, until its source code was released in 2008. Antares is a port of Ares's 2008-released source code to modern Linux and macOS systems. It launches through a plugin picker that defaults to the original Ares scenario, and the window can simply be resized or maximized since there is no dedicated video-settings menu.
How it differs from the original
The project is not yet feature-complete: several issues remain to be fixed before a 1.0 release, after which Antares is expected to reach full feature parity with Ares except for multiplayer, which has no firm timeline.
Getting started
Build it from source using its standard build scripts (the configure step will list any extra dependencies you need), then launch it; a launcher screen lets you pick which plugin or scenario to play, with the original Ares scenario included by default. On Linux it can optionally be installed system-wide, and on Mac the built app can simply be moved to the Applications folder.