Choose a window
All of these open the same world. None of them is it.
The flat window
tiles, from above
Every tile plain and legible, the whole neighbourhood at a glance. It asks very little of a machine and reads well on a small screen. If you are not sure, start here.
EnterThe lantern window
forty-five degrees, and one light
The same island with the camera turned, so that things stand in front of other things: you walk behind the oak and in front of the wall, and a building has two sides to it. Warm light, cool shadow, and no morning. The world’s clock still turns and every other window will show you the sunrise, but this one keeps its lantern lit and declines to look. Anything lying on the floor stands in a pillar of light, and everything that lands says how much.
EnterThe holo window
a diorama on your table · experimental
The world as a small country placed on a real surface, or at full size around your feet. Built for headsets that pass the room through, and it runs flat in an ordinary browser too. Air-tap a tile to walk to it.
EnterAll of them open in this browser, and nothing is installed. Nothing is chosen for good either: leave by one door, come back through another, and you are the same citizen in the same place. Standing, calling and inventory are identical in every one, because none of that is the window's to decide.
A window is not the world
The world is not in either of these pages. It is a protocol: a rule for turning one state and a set of deeds into the next state, agreed six hundred milliseconds at a time by every node that runs it. Interval is that agreement. Everything you see here is one program's opinion about how to paint it.
Which means none of these is the client and the rest the alternatives. They are windows, written first, out of the same protocol anyone else can read. A window that draws the world in a terminal, or reads it aloud, or paints it on a headset, or fits it into a watch face, is not a lesser way to play Interval. It is Interval, seen from somewhere else.
What the world insists on
A window may choose its colours, its camera, its sounds, whether to show a map at all. It may not choose what is true. Where a citizen stands, what they carry, which country they are in, how much of the world they have touched: all of it is settled by the protocol before any window opens, and every window that reads the same tick must agree about every one of them.
That line is drawn deliberately, and it is drawn tightly. Two people who disagree about where the Fens end cannot arrange to meet there, so geography is law. Two people whose windows report different levels for the same citizen do not have a disagreement about pixels, they have a disagreement about a person, so standing and calling are law. Almost nothing else is.
Write your own
The state of the world is public and readable over a plain HTTP endpoint, and a window needs nothing more than that plus the ability to sign a deed with a key. No permission, no registration, no approved client list. If your hashes match, you are a citizen, and so is whatever you wrote to look at it with.
Two others ship with the node and are not listed here: a deep window that puts the camera behind a citizen's shoulder, and a photo window that holds it at eye height. Both still open, both still read the same tick, and neither is kept up any more. They are left in because a window nobody maintains is still a window, and because the point of this page is that anyone may write one, which is worth less if the ones that fall behind quietly disappear.
The manual documents the state and the rules. The New Player Guide gets you playing in ten minutes. Every one of them ships with the node, and every one is yours to take apart.