You've discovered Iterations! This is a Vanilla+ SMP where the core game still feels like Minecraft, just with a lot more to do around it. The server mixes in Towny, SiegeWar, Movecraft, Economy, QuickShop, custom terrain, custom crafting, Jobs, BreweryX, and vote and donor rewards, so there's plenty of room to build, trade, fight, or just settle in and play your own way.
Build up a big city with Towny and gather citizens around you, or stay neutral and keep things peaceful. If war is more your thing, SiegeWar lets towns take on their enemies, while Movecraft opens the door for airships and bigger war machines. You can also haul resources between ore nodes, sell to other players, and use the economy to fund whatever project you're working on.
There's a Build world for players who want to design and create, and a Survival world for anyone who wants to rough it in the wilderness. Jobs give you a steady way to earn money through normal gameplay, and QuickShop makes player trading a big part of the server loop. On top of that, you'll find a helpful, welcoming community with lots of freedom in how you want to play.