OpenTS Co-op

Tiberian Sun, rebuilt: shared-house co-op campaigns — several players, one force.

launcher lobby experimentallauncher lobby

0.7.0 preview · 2026-10-16 · release notes

A fork of OpenTS, the open rebuild of the Command & Conquer: Tiberian Sun engine, with selectable campaign mission variants and a player-by-force control matrix: several players can share a force, and one player can control several.

The Warpzone launcher can stage its network games without port forwarding by tunnelling the game's UDP traffic.

You need: original Tiberian Sun + Firestorm data; Windows (or Wine)

What's new

From the project's release notes. Games and the launcher show these after every update.

Co-op campaign preview 0.7.0 preview

2026-10-16 · on GitHub

Campaigns named by identifier in launch files. This is a preview build of commit 37fef62.

A SPAWN.INI can now name its campaign with Campaign=, such as Campaign=GDI1, instead of numbering it with CampaignID. Without a Scenario, the launch starts that campaign's first mission. The identifiers are the entries of the battle files' [Battles] list, so one launch file starts the same campaign on installations whose battle files number the campaigns differently. On a CnCNet install, the old guide example CampaignID=0 named the list's header entry rather than the GDI campaign; the guide now uses Campaign=GDI1. The Warpzone launcher's co-op lobby will use this key to start shared-house campaigns.

Start with hand-written launch files · A campaign mission

VS2022 Win32/x64 Debug/Release builds and CTest passed on this commit, together with Manual CI. A campaign launched with Campaign= was not tried on real machines before this release.

0.7.0 does not list or load saves written by 0.6.0. All players need this exact fork build and the same target platform. Original game assets are required and are not included.

The release workflow attaches separate Win32 and x64 engine packages.

Send bug reports and requests for this fork to <https://ntfy.sh/opents-coop-feedback-496c07> (web page, ntfy app, or curl -d "your message" https://ntfy.sh/opents-coop-feedback-496c07). The channel is public, so leave out personal data.

New features

Name a launch file's campaign by its identifier (by jarvis-jhk)

Co-op campaign preview 0.6.0 preview

2026-10-16 · on GitHub

Waypoint paths in shared campaigns. This is a preview build of commit cd98e94.

Every player in a shared-house campaign can now use waypoint mode: plot paths, loop and edit them, and send units along them. Each player sees only their own paths. A unit follows the path of the player who sent it, and an order from another player takes it off that path. With several forces, a click on a waypoint sends only the selected units of the force shown on the sidebar along the path; the other selected units get the order a click on that cell gives them without a path. That last change also fixes a crash in one-player campaigns with several forces when a mixed selection was sent to a waypoint.

Runtime limits · Waypoint paths

VS2022 Win32/x64 Debug/Release builds and CTest passed on this commit, together with Manual CI. Waypoints in a running shared campaign were not tried on real machines before this release.

0.6.0 does not list or load saves written by 0.5.0. All players need this exact fork build and the same target platform. Original game assets are required and are not included.

The release workflow attaches separate Win32 and x64 engine packages.

New features

Plot waypoint paths in shared campaigns (by jarvis-jhk)

Co-op campaign preview 0.5.0 preview

2026-10-16 · on GitHub

Save and resume shared campaigns. This is a preview build of commit 366d83d.

In a shared-house campaign, Save Game in the options menu now saves on every machine at once, and automatic saves follow the host's automatic-save setting. The host can load one of the current mission's saves during play from the options menu. To continue another day, the same players meet in the network lobby again; the host clicks Load Game instead of Campaign, picks the save, every guest accepts, and the host clicks Go!. Every player of the save has to take part again under the same name. Starting the next mission deletes the previous mission's saves.

This release also carries the upstream fixes merged since 0.4.0: blitter depth and alpha drawing, repeated kills during vehicle death animations, additive armor and firepower crate upgrades, missing UI resources and empty map lists, and message commands grouped under Interface.

Save and resume · Detailed rules

VS2022 Win32/x64 Debug/Release builds and CTest passed on this commit, together with Manual CI. The lobby launch files for a resume are covered by the SpawnContract test. Saving, loading and resuming a shared campaign in a running game were not tried on real machines before this release.

0.5.0 does not list or load saves written by 0.4.0. All players need this exact fork build and the same target platform. Original game assets are required and are not included.

The release workflow attaches separate Win32 and x64 engine packages.

New features

Let armor and firepower crates add to the multiplier (by ZivDero)
List the chat commands under Interface (by ZivDero)
Save and resume shared campaigns (by jarvis-jhk)

Bug fixes

Correct sprite depth and lighting (by ZivDero)
Prevent repeated kills during vehicle death animations (by ZivDero, JoyfulShush)

Open rooms

No open rooms right now. Host one from a game or the launcher.

Mods

Categories: Maps, Mission variants. Every mod version is reviewed by a moderator before it appears.

No mods published yet.