Around 2009 somebody came up with the idea of marrying Inform7 games with multiplayer, he called it Guncho. I am not entirely sure how this differs from regular MUD playing but I can imagine it's very nice if you want to explore the same atmospheric 'realm' together. A realm that's easily build with the excellent Inform7 natural language tools and world simulation. The only obstacle is finding players to play the game. The platform is C# and open source, I like the idea so much I'm installing it now on my own machine. https://www.guncho.com/