From Exodus3000 Wiki

Browser based means that the game is played in an normal internet browser window - no installation is necessary to play Exodus3000.

However, to use the in-game chat-room (messaging tool) you will need to have a version 1.1.x compatible Java Virtual Machine installed on your computer. If you cannot see the chat-room you can download the Java Virtual Machine here.

Exodus3000
Statistics	Weapons | Defense | Intelligence | Security | Radar
In-game Elements	Dig | Cards | Missions
In-game Locations	Mars | Homestead | Abandoned Homesteads | Settlements | Outposts | Volcanoes | Ruins | Craters | Plains | Dunes
Rules and Regulations	Alliances | Basics | Cheating | Payouts | Purchases | Special Prizes | Referrals | Cards | Dig for Treasure
Official Website	Official site