Life is Feudal: Your Own has been around for a while, but you probably first heard of the franchise when it popped on Steam on November 17, 2015. It holds similarities to Rust, DayZ, and other sandbox survival games in that you start with basically nothing, and are expected to build yourself up -- crafting weapons to deal with other players, building a home, finding friends to gang up on others with or huddle for protection.
In those games, you popped into a server of your choice, and your progress was tethered to it. Logging into a different server and was like starting fresh again.
Life is Feudal seeks to unify its playerbase with a MMO format. The idea is that instead of creating one massive open world, they have several servers that each worry about one section of the map. When you move from one map border to the next, you hop over to that server. These chunks are absolutely massive, each one roughly the size of the current game's map.
Similar to how the Elder Scrolls franchise handles it, your skills increase as you use them. More advanced skills are blocked off until you've leveled up the ones leading up to them. For example, you need to train as your construction skill to become a mason, then work on masonry until you become an architect. With skills taking a long time to level up (and there being a high level cap for the skills), it promises that it'll take a while to reach the heights of players who've been around for a while.
The Life is Feudal MMO is currently in beta, so it has its fair share of bugs. Only long-time fans and promoters are being given access to it at the moment. Keep an eye out for this hardcore survival game when it releases.