Sindome was the first MUD/MOO I ever played. That was 15 years ago. I've been playing it ever since. There are still parts of the world I have yet to explore, NPCs I have yet to interact with, roles that my various characters over the years have not even come close to playing let alone mastering. The game has a rich, 20+ year In Game history. There are tons of resources to help you learn the game, including a YouTube series which introduces the commands. The staff are all volunteers, and a lot of focus is put on training them to handle NPCs consistently and to run plots that keep with the cyberpunk theme. If you haven't checked this game out, you should.
Sindome is a true roleplaying game that brings an extensive set of character customization options to the player. Unlike games where you are forced to select a rigid class for your character, Sindome allows you to customize your character by assigning a mix of skills. While there are some recommended combinations of skills for certain types of roles, it's more than feasible to venture outside these recommendations and create a truly unique character. Additionally, character progression is tied to roleplay, which increases the interaction between characters and ensures that grinding is not necessary or even useful. Other systems like combat and hacking are well fleshed out. Although some systems still appear to be in the works, there is quite a lot already available to play with.
As far as minor features go, Sindome is quite extensive. The ability to customize crafted items is nice. The equipment system, which allows for layering and hiding certain parts of the body, as well as describing exposed parts, is useful and certainly better than having a rigid, single, unchangeable description, although the way it works can be a little difficult for a newbie to figure out at first. Overall, there's a lot to experiment with in terms of crafting.
Set in a dystopian alternate future, Sindome's setting focuses on the stratification of society. The poor are forgotten, left to fend for themselves somehow or find a way up the metaphorical ladder. That ladder isn't as metaphorical as you'd think, with each tier of the city literally above the other. The introduction to the game leaves you at the lowest level of society, and it's up to you if your character has found his or her level in life, or wants to ascend.
Besides a few bad apples, the community is friendly and welcoming overall, especially to new players. It's a hidden gem of roleplay-required games: when certain RPIs are often touted as being the only roleplaying MUD with a high player count, Sindome in fact has a similar number of active online players or more every night, and is actually built on a system designed for roleplaying.
Like the player community, the staff do struggle at times with tact. But they are able to recognize their own faults and step into other roles for the benefit of the playerbase, which demonstrates to me that they truly care about the game and not about the power they have as staff members; a rare find in the MUD community overall.
Although some players can be more expressive than others, it's clear to me that everyone tries to have a good time in Sindome, and that everyone tries to play a consistent, fleshed-out character. I was impressed by more than a few players, but was never unimpressed by anyone. Just like a well-produced TV show or a well-written book, you have characters you enjoy and characters you tolerate as being a part of the story, but you don't hate the actors or the author.
The first thing to say is if you don't have patience, willingness to learn, and time to understand the in depth way this MOO works then it might now be for you. But since I started this MOO nearly a year ago I haven't stopped playing and don't intend to despite the learning curve.
If you are looking for in depth RP with heavy themes, challenges, and a great community then this is for you.
If you are looking for hack and slack, don't like much roleplay, and want to get gear and be elite, then this is not for you.
Sindome is about a single character surviving in its challenging world using an intuitive system, but you can forget about how all the coding, stats, and math works because this game is about the story and the roleplaying. Check out their website for more info, and play it if you agreed with my above pros.