It's called Pardus. It's a free web based browser game. It is simple but amazing. I never thought I would like a browser game like this. Ok, maybe not simple, but the basics are easy enough to understand.
A link:
http://www.pardus.at/index.phpThe premise is simple: A huge galaxy that you can explore in and build buildings. Combat is done in the form of rounds.
First off, you start off with 5000 APs, or action points. You get 24 every 6 minutes. almost everything pertaining to advancing in the game costs action points. You can trade with starbases and planets, or, player owned starbases and buildings. Lots of ships to upgrade to. This game takes a while to progress in, but is fun to do so in. The economy is really good. If you don't have enough traders in your area, your buildings and planet in the sector might stagnate. This rarely happens, but I have seen some systems fail or just have no one upkeep them.
Combat takes place by "Walking" onto a square with a monster in it. Be aware, this is a sci fi space game, so you will fight enemies in ships. You may select up to 20 rounds of combat, but I wouldn't do that, even with a space maggot, until you have a decent gun and some armor. It is sort of like DnD style combat, but instantaneous. You have stats which increase by fighting "Worthy" Monsters. After you have spent 50,000 aps, you can now attack other people if you wish, and raid their buildings.
Definitely worth it. There is a premium option where you can have a slightly increased AP maximum (5,600 I think,) But they definitely don't shove money buying down your throat like most MMO RPGs. Indeed, I am competing quite well with several premium players.
All in all, PLEASE give it a try. People are leaving the game and it is dying after 5-6 years. The developers don't deserve it: They've made a wonderful game and are STILL updating it.