FreeCiv 2.6.2

Civilization is one of the most popular 4X games in the world, helping to popularize the genre since way back in the day. However, some players believe that as they changed to appeal to more and more people over the years, they've also simplified a ton of mechanics to become a bit more mainstream. Some of these people decided to make an open source version of one of the earliest games in the series - FreeCiv.

To install FreeCiv, simply run the installer and you're good to go.

This game is based on Civilization 2, which was just about when the game got more complicated. That makes this game have a pretty steep learning curve, but the core of it is much the same if you've played any other 4X game. You have to manage your city's specialists and decide which resources you want to develop, a city can only grow if certain buildings are built, so on and so forth.

The research is also handled slightly differently. You can spend a certain amount of income and build special buildings inside your cities to increase your tech level, or simply trade research with other players. There's a rather large tech tree that you can find at any point in the help menu.

Overall, if you're a dedicated and enthusiastic 4X player, then you should definitely take a look at this. It's constantly being updated and has a thriving playerbase. If any of that sounds like it appeals to you, then you should definitely give FreeCiv a download.