Ludovic MarieandClaude Opus 5.5
0e65e85878
Ludovic's decision (2026-10-23): no more Alpha and Stable. release.yml publishes every game release as the release and GitHub's latest instead of a pre-release that promote.yml made stable once a day. The checks that gated a promotion run in the release itself: `decide` holds the train while an issue labelled release-blocker is open (forced runs too), and the publish job runs `release_train.py gate` right before publishing: the Mac mini's smoke-test.json must be there and show a world was drawn, and no blocker may be open. Otherwise nothing is published. Notes cover everything since the last release that is not a pre-release, so the first single-channel release lists all of it since v0.2.0. promote.yml, tools/release_channels.py and its tests are deleted. The cadence is unchanged (5 minutes of settling, 20 at most, release-now at once). Docs and site: one channel in release-flow, versioning, security, the FAQ, install, the home page and the Releases page (Game / Launcher filter); no player-facing Alpha wording left. Co-Authored-By: Claude Opus 5.5 <[email protected]>
4.7 KiB
Install and first launch
Download the launcher, let it install Horizon, then prepare the game from your own copy of Minecraft. It takes a few minutes, and you do the preparation once.
What you need
- Minecraft: Java Edition 26.3, played once. Install it with the official Minecraft launcher (or Prism Launcher, MultiMC, the Modrinth App, ATLauncher or GDLauncher) and start 26.3 once, so it downloads its files. Horizon reads them from there and never copies them anywhere else.
- Java 25, a JDK, for the one-time preparation only (the game itself needs no Java). Nothing to install: the launcher uses the Java the Minecraft launcher downloaded for 26.3, or downloads that same Java from Mojang. A JDK you installed yourself (for example Eclipse Temurin 25) works too.
- A computer on the supported list. On Linux and Windows that means a graphics card with Vulkan (or DirectX 12 on Windows).
Download the launcher
Get the newest launcher from the Download button on the home page, which picks the right file for your system, or from the launcher releases on GitHub.
- Linux: download
horizon-launcher-linux-x86_64.tar.gz, extract it and runhorizon-launcher. - macOS: download
horizon-launcher-macos-arm64.dmg, open it and drag Horizon onto Applications. The first time, macOS says it cannot check the app, because it is not signed with a paid Apple developer account. On macOS 14 and earlier, right-click Horizon, choose Open, then Open again. On macOS 15 and later, open it once, then go to System Settings, Privacy & Security and choose Open Anyway. After that it opens normally. - Windows: download
horizon-launcher-windows-x64.zip, extract it and runhorizon-launcher.exe.
Every release also carries SHA256SUMS and a signature, SHA256SUMS.sig, if you want to check your download. The launcher does not check that signature for you yet.
First launch
- Open the launcher. On the Play page, if it says "No version installed yet", choose Choose a version. On the Versions page, install the newest one. The launcher installs it in its own folder.
- Back on Play, the launcher says "Not prepared. Horizon needs the files of your own Minecraft 26.3." Choose Prepare. It finds your Minecraft folder by itself in the usual places. If it cannot, it lists where it looked, and Choose… next to the Minecraft folder lets you point it at yours.
- Wait a few minutes. When it says "Prepared for Minecraft 26.3", choose Play.
The game opens on vanilla's title screen. Your worlds, options and logs live in the game folder, which is not inside a version's folder, so updating or removing a version never touches them:
- Linux:
~/.local/share/horizon - macOS:
~/Library/Application Support/horizon - Windows:
%APPDATA%\horizon
No Microsoft sign-in yet. The launcher's Settings page has an Accounts section, but signing in with a Microsoft account does not work for players today. It needs an app registration and an approval from Mojang that the project does not have yet. You do not need an account to play single player.
Updating
- Horizon. The launcher looks for a new release when it starts and every 30 minutes while it is open. With Install new versions automatically on (the default), it installs one and moves you to it if you were on the newest. New releases come out many times a day, and old versions stay installed until you remove them on the Versions page.
- The launcher. It updates itself from its own releases, then shows Restart in its footer. A launcher from before 0.2 (0.16 or older) updates twice in a row: first to 0.17, then to 0.2. Then it installs Horizon 0.2 like any update.
One version for everyone
There is one channel: every release is the version everyone gets. Before a release goes out, the game has to start and draw a world on our test machine, and nothing goes out while a serious problem is open. New releases come out many times a day, and you can install any older version by hand on the Versions page.
Launchers from before this change still show an Updates choice in Settings. Either option now gets every new release, and the choice goes away once the launcher has updated itself.
The Versions page
It lists Horizon's releases, newest first. You can install a version, remove it, or choose which one Play starts. Each release's notes are on the Patch notes page, and on GitHub.