ATMOS-X is a free community weather and atmospherics mod for DCS. It is not ours and we do not sell it, but we can set your server up so your group can fly with it. Here is exactly what that involves, and what to expect in multiplayer.
ATMOS-X is a third-party mod for DCS World, made and supported by its own author and distributed free (with a donation link) from atx4dcs.com. It adds new cloud presets, detailed high-altitude cirrus, aurora borealis, shooting stars, richer lightning and thunderstorms, and better star and moonlight lighting. It also ships planning tools, including a cloud builder that can match a real METAR report.
It installs on your PC, not on the server. Fox3 does not build, sell, or bundle ATMOS-X, and we cannot fix bugs inside it — for problems with the mod itself, go to the author. What we support is the server side: making your Fox3 server accept players who are running it.
DCS servers can require that every connecting client is running unmodified game files. This is called the integrity check, and Fox3 servers have it switched on by default. ATMOS-X changes DCS files, so with the default setting your pilots would be refused when they try to join.
On request we turn the integrity check requirement off for your server. That is the whole server-side change, it takes effect on the next restart, and we can switch it back at any time. Open a ticket in the Fox3 support channel with your server number and ask for ATMOS-X support.
Custom cloud presets do not carry over to the server.If you build your own preset in the ATMOS-X cloud builder and save it into a mission, your Fox3 server will not have that preset and will quietly fall back to default clouds for everyone. The mission still loads and the server runs normally — the weather is simply not the weather you designed. We tested this directly. If you want your authored weather to arrive intact, build your mission using DCS's own stock presets; everything else ATMOS-X does, including the cirrus, lighting and atmospheric work, still renders for each pilot.
Turning the integrity check off applies to your whole server. It is a single server-wide setting, not a per-mod one, so once it is off your server will also accept clients running other modified files. If your group runs competitive or scored events where that matters, think about it before asking.
Pick one. The Fox3 Real Weather add-on writes live real-world weather into your mission, and ATMOS-X also writes weather into missions. Running both means whichever writes last wins, and the result is unpredictable. If you want real-world weather driven automatically, use Real Weather. If you want hand-authored skies and the ATMOS-X visuals, use ATMOS-X.
We do not install ATMOS-X on the server itself, and we do not copy custom cloud preset files into the server installation. Doing that would mark the server as modified and it would be undone by the next DCS update, so it is not something we can support reliably. If that limitation is a problem for what you are planning, open a ticket and describe what you are trying to achieve — there may be a better way to get there.
Open a ticket in the Fox3 support channel with your server number and say you want ATMOS-X support. We will confirm the setting is changed and when it takes effect. Questions about the mod itself, its features, or its installer belong with the ATMOS-X author at atx4dcs.com.