In reply to @dandellion:dodsorf.as
including puppeting ones, and more radical ones

Answering myself:

This is a richer form of bridging, where the bridge logs into the remote service as if it were a real 3rd party client for that service. As a result, the Matrix user has to already have a valid account on the remote system. In exchange, the Matrix user ‘puppets’ their remote user, such that other users on the remote system aren’t even aware they are speaking to a user via Matrix. The full semantics of the remote system are available to the bridge to expose into Matrix. However, the bridge has to handle the authentication process to log the user into the remote bridge.

In reply to @uver:matrix.org
I don't think this is right place. I just need suggestions for the correct DNS settings for hosting my own server on my own domain using the example in the manual.

I wrote a k-d-tree generator in nix

with builtins;
let fold-shim = { _type = [ "magic" "fold-shim" ]; _empty = true; };
    skip-shim = f: a: b: if a == fold-shim then b else f a b;
    sort-by = f: sort (a: b: f a < f b);
in rec { get-k-d-tree-from-point-set =
  { dimensions ? builtins.foldl' (skip-shim (a: b: if a > b then a else b)) fold-shim point-set, 
    point-set ? [ ], cut-direction ? 0, default-coordinate ? 0 }: if length point-set != 0 then
    let get-coordinate = point: if length point >= cut-direction then elemAt point cut-direction else default-coordinate;
        point-count = length point-set;
        sorted-points = sort-by get-coordinate point-set;
        median-point = elemAt sorted-points (floor (point-count / 2));
        cut-position = get-coordinate median-point;
        remaining-points = filter (point: point != median-point) sorted-points;
        partitioned-points = partition (point: get-coordinate point > cut-position) remaining-points;
        next-cut-direction = if cut-direction + 1 == dimensions then 0 else cut-direction + 1;
    in { _type = [ "k-d-tree" "node" ];
         point = median-point;
         lt-leaf = get-k-d-tree-from-point-set {
           point-set = partitioned-points.wrong;
           cut-direction = next-cut-direction;
           inherit dimensions;
         };
         ge-leaf = get-k-d-tree-from-point-set {
           point-set = partitioned-points.right;
           cut-direction = next-cut-direction;
           inherit dimensions;
         };
         inherit dimensions cut-direction; }
    else { _type = [ "k-d-tree" "leaf"];
           _empty = true; }; }