All [Unix like systems](https://en.wikipedia.org/wiki/Unix) with either [X11](https://en.wikipedia.org/wiki/X_Window_System) or [Wayland](https://en.wikipedia.org/wiki/Wayland_(protocol)) are well supported since ever.
Over the years it was, like most of the [KDE applications](https://apps.kde.org/), ported to various [BSD](https://en.wikipedia.org/wiki/Berkeley_Software_Distribution) variants.
Be it some mainstream Linux distribution like [Fedora](https://fedoraproject.org/) or a niche one like [NixOS](http://nixos.org), Kate is available as binary package.
Since several years there are activities in the KDE community to provide our libraries and applications for [Windows](https://en.wikipedia.org/wiki/Microsoft_Windows).
Even if that is a non-free platform, we can reach out to new users and developers that might later be then even interested to switch a full open platform.
We have Kate and some other applications in the official [Windows Store](https://apps.microsoft.com/search/publisher?name=KDE+e.V.) and nightly build for more of them.
With reasonable effort you can develop Kate on Windows with [Craft](https://community.kde.org/Get_Involved/development/Windows).
We have nighly build available for that and you can, like on Windows, develop Kate with the help of [Craft](https://community.kde.org/Get_Involved/development/Mac).
Same as for Windows, if you like to try that, use the nighly installer for either ARM or Intel Macs linked on the [Kate website](https://kate-editor.org/get-it/).
Beside the mobile ones like [Android](https://en.wikipedia.org/wiki/Android_(operating_system)) and [iOS](https://en.wikipedia.org/wiki/IOS) that are not that interesting for Kate, many other desktop operating systems exist.
For Kate, testing should be easy, grab a nighly build for Windows or macOS on the [Kate website](https://kate-editor.org/get-it/).
Or even better, get [Craft](https://community.kde.org/Craft) running, that will make it easier to contribute, too.
One recent topic that needs love is the removal of [DBus](https://en.wikipedia.org/wiki/D-Bus) for Windows/macOS/Android and other systems that don't use it normally.
The current state is already sufficient that the nightly builds of Kate no longer hang on e.g. macOS, but still some frameworks like KIO will need more work.
Just don't get that wrong, DBus is great on the Linux or BSD systems that use it natively, but it is a pain on systems that have no notion of DBus and leads there to hangs or the spawning of unwanted processes.