scrolling thru the post the NeoTokyo screenshot struck me instantly, I ran through the hallway thousands of times - I ran a server for that mod for some years and had great fun with a small community of good/capable people.

The even more amazing thing is that it's still actively played. There is a full server every Friday night (sometimes also in Saturday/Sunday). It has got some quite dedicated fan base and I've never seen such dedication in another old multiplayer game.